Vol. 4 No. 3
Michigan DairyReview Progressing Toward the 21st Century
Johne’s Disease 101: A Basic Introduction Dan Grooms Dept. of Lg. Animal Clinical Sciences
ohne’s disease (pronounced Yonees) is a serious disease of cattle, which can cause significant economic loss if not controlled. A recent survey found that approximately 55% of Michigan dairy herds contained at least two cows infected with the Johne’s disease organism. Despite this, many cattle producers are unaware of the disease and the potentially devastating effect that it can have if left unchecked. Fortunately, some basic knowledge about Johne’s disease can go a long ways towards getting a handle on this serious disease. The Organism Johne’s disease is caused by a bacterium called Mycobacterium avium subspecies paratuberculosis. Other than on artificial media, this bacterium only grows inside cells of a living animal. However, it can survive in the environment for at least 1 year and probably longer. When an animal becomes infected, the bacterium grows very slowly. In fact, once an animal is infected, it can
Tri-State Dairy Meeting Set for Nov., 10-11 The Tri-State Dairy Management Conference is scheduled for November 10-11, 1999 in Ft. Wayne, IN. Registration materials are on pages 21-23 of this MDR issue.
take years for the bacterium to replicate enough to cause clinical disease. Animals affected by Johne’s disease include cattle, sheep, and goats. A Unique Disease Johne’s disease is unique in that the initial infection usually occurs years before clinical signs of the disease are seen. The majority of cattle become infected with the causative agent of Johne’s disease as calves less than 6 months of age. As cattle get older, they become less susceptible to infection with Johne’s. Calves become exposed to the bacterium by ingesting material contaminated with the Johne’s disease organism. The bacterium then infects and replicates in the small intestines. As the bacterium grows slowly over time, the animals immune system tries to attack the bacterium. Unfortunately, the immune response is usually ineffective in eliminating the bacterium. In fact, a combination of the growing bacteria and the immune system response leads to chronic damage of the intestines. This damage, which can take years to occur, eventually results in diarrhea and weight loss despite a good appetite; these responses are the characteristic clinical signs of Johne’s disease. Once clinical signs begin, progression of the disease is very rapid and cows may become debilitated within a matter of weeks. Before diarrhea and weight loss begin, there is evidence that the smoldering disease may contribute to an increased rate of other problems in infected cattle.
Dr. David K. Beede Department of Animal Science Michigan State University Anthony Hall East Lansing, MI 48824-1225 Phone (517) 432-5400 Fax (517) 432-0147 E-mail [email protected]
MICHIGAN STATE UNIVERSITY
Contents Johne’s Disease 101 .............. 1 Bovine Salmonellosis .............. 3 Stress and Immunity at Calving .......................... 5 Microorganisms in Raw Milk ... 7 1998 Dairy Business Analysis . 9 Is Your Farm Equipped for Reproductive Success? ..... 10 Udder Issues ....................... 13 State’s Milk Market Update .. 14 Bill Thomas Honored ............ 15 MSU Highlights at ADSA ...... 16 Introducing the Graf Scholars 19 Corn Harvest 1999, Consider .... Your Options .................... 19 Calendar of Events ............... 20 Tri-State Dairy Management ..... Conference ....................... 21
2 MICHIGAN DAIRY REVIEW This is referred to as subclinical Johne’s disease. These problems may include low milk production and increased susceptibility to other infectious diseases such as mastitis. The Transmission The primary source of infection is feces, which contains the causative bacteria. Infected cattle can produce large amounts of the bacterium and shed this organism in their feces. Typically, in cows with clinical Johne’s disease (diarrhea and weight loss), 1 gram of feces can contain 1 billion Johne’s disease organisms. Even infected cattle not yet showing the typical clinical signs of diarrhea may shed the bacteria in their feces. Most infected cattle do not begin shedding the Johne’s organism until they are adults. Calves less than 6 months of age are most susceptible to infection. Any method by which calves become exposed to fecal material from adult cattle may serve as a source of infection with the Johne’s disease organism. This may include being born in a dirty maternity pen, nursing a dirty teat, being housed in direct contact with adult cows, using common feeding/manure handling equipment (skid-loader) or manure run-off from mature cow areas going through the environments of young calves. Another important source of transmission is milk and colostrum. About 1/3 of cows infected with Johne’s disease, whether they are showing clinical signs or not, will shed the bacteria in their colostrum or milk. Feeding colostrum or milk to young calves that is contaminated with the Johne’s organism can lead to their infection with the disease. Finally, calves can become infected before they are born. Approximately 20% of cows with Johne’s disease will pass the causative bacteria across their placenta to the developing fetus. The risk of this happening increases dramatically in cows with clinical signs of Johne’s disease. Diagnosing Johne’s Disease Chronic diarrhea, rapid weight loss and good appetite in cattle older than 2
AUGUST 1999 years of age is highly suggestive of Johne’s disease. These findings warrant further laboratory investigation. There are two basic ways to diagnose Johne’s disease in cattle. The first is to identify the organism in the feces of an infected animal. This is most commonly done by culturing feces for the Johne’s bacteria. Unfortunately, shedding of the bacteria in feces does not start until later in the progression of the disease. In other words, although infected with Johne’s disease as a calf, cattle usually do not shed the bacteria in feces until the disease has progressed during adulthood. Therefore, cattle early in the course of the disease that are not shedding bacteria in their feces will be missed using fecal culture. Another problem with culturing for Johne’s organisms is that it takes between 8 to 16 weeks for the bacteria to grow. This is a problem when rapid answers are needed concerning the status of an animal or herd. New and faster methods are being developed to identify the Johne’s disease bacteria earlier in the course of the disease, but are not yet available. The second method of diagnosing Johne’s disease is to look for an immune response by the infected animal to the Johne’s organism. Currently, the most commonly used test is called a Johne’s ELISA. This test identifies antibodies that are produced by the cow in response to the Johne’s disease bacteria infecting the intestinal tract. However, as with fecal shedding, the development of these antibodies is slow to occur. So, although infected as a calf, an immune response sufficient enough to produce detectable antibodies usually does not occur until adulthood. Again, the further the disease has progressed, the more likely that detectable antibodies are being produced. Therefore, cattle early in the course of the disease that have not mounted a sufficient immune response will test negative on the Johne’s disease ELISA (false negative). A general rule of thumb is that if all cattle 2 years of age and older are tested for Johne’s disease, the ELISA will identify 50% of the infected cows. The advantage of
the ELISA test is that it is rapid and relatively inexpensive. Other immunological tests are being developed which again are aimed at diagnosing infected cattle earlier in the course of the disease. Control and Prevention Because of the nature of the disease, the number of cattle infected with Johne’s disease will increase over time if control measures are not instituted. There are two major strategies used to control Johne’s disease: 1) identify and eliminate infected cows, and 2) reduce the risk of calves becoming exposed to and subsequently infected with the Johne’s organism. Identifying infected cows requires the use of one of the diagnostic tests described previously. The cows most important to identify are those shedding the Johne’s organism in their feces as they serve as a source of infection for young calves. Fortunately, most cows that are shedding bacteria will be positive on diagnostic tests. Cows that are identified as Johne’s disease positive should be culled from the herd. It should be noted that daughters from Johne’s positive cows are at higher risk for being infected with Johne’s disease because of transmission of the organism in utero and through colostrum and milk. Purchased cattle should be screened for Johne’s disease before entering the herd. Unfortunately, the diagnostic test may not detect all infected animals, especially in younger cattle. Therefore, purchasing cattle from Johne’s certified free herds or herds with no history of Johne’s disease should be attempted. By doing this, the risk of introducing the disease into your operation is reduced significantly. Good management of calves is important to reduce their risk of being exposed to the Johne’s organism. The first step is to make sure that calves are born in a clean, manure free environment. Calves should then immediately be removed from their dams. Colostrum should be fed from Johne’s negative cows only. If the Johne’s status of cows is unknown, feed colostrum from indi-
MICHIGAN DAIRY REVIEW 3
vidual dams to their calves only. Do not pool colostrum because this increases the risk of spreading Johne’s disease from one infected cow to many calves. Following colostrum, a high quality milk replacer should be fed. Feeding of pooled waste milk can infect many
calves if any cows are shedding the Johne’s disease bacteria in their milk. Calves should be housed separately in a clean environment that has no contact with the adult herd. Equipment that is shared between the calf and cow environments should be properly disinfected
Bovine Salmonellosis Robert E. Holland Dept. of Lg. Animal Clinical Sciences
almonella serotypes are widespread throughout the United States, causing a variety of clinical diseases and nonclinical infections. Although salmonellosis affects cattle of all ages, the disease is most severe in calves and stressed adults in herds with chronic infections (endemic herds), and at all ages in herds that have not been exposed previously (naive herds). The two most common serotypes causing bovine salmonellosis are S. typhimurium and S. dublin. In Michigan, S. typhimurium is the most common serotype isolated from dairy cattle. S. typhimurium lacks host specificity and can infect and cause disease in a variety of animals and humans. S. dublin is highly adapted to cattle, but may cause disease in humans. Clinical Presentation We often discuss clinical salmonellosis as an acute to chronic diarrheal disease. Indeed, diarrheal disease gets the producer’s and veterinarian’s attention. However, it is important to remember that salmonellosis in a herd or in an individual animal may occur in a number of different syndromes. Salmonella infections may result in diarrheal disease, systemic disease, or in abortions. Diarrheal disease may be observed as an acute condition with the passage of voluminous, foulsmelling feces containing mucus, intestinal casts, and blood. Lactating cows also may experience a mild -to- moderate diarrhea that is accompanied by severe metabolic consequences. These metabolically compromised cows may experience electrolyte imbalances, ketosis, and displacements of the abomasum. Diarrhea also may occur infrequently as a low grade diarrhea during times of stress. In this case, other than the diarrhea, the affected animals may appear healthy, yet shed large numbers of the organism into the environment. Systemic disease or septicemia is accompanied by high rectal temperatures, disinterest in eating, and a rapid drop in milk production. Some animals will die before the appearance of diarrhea or other clinical signs. In calves, septicemic salmonellosis may occur as an acute respiratory disease. These calves often die before the appearance of profuse, bloody diarrhea. Calves that survive the acute phase may have infections involving the central nervous system, liver, kidneys, and multiple joints (polyarthritis).
or, if possible, avoided. Good biosecurity should be practiced among personnel that handle both adult and young cattle. This includes washing hands and cleaning and disinfecting boots and clothing.
In herds with cows experiencing high rectal temperatures, a sudden drop in milk production, and abortions, systemic salmonellosis should be considered in the diagnostic evaluation. Although S. dublin is most often incriminated in systemic disease and abortions, other serotypes may cause abortions. If the fetus is infected in very late gestation, the calf will be born alive but infected with Salmonella. An animal’s response to Salmonella exposure and therefore the seriousness of disease depends on several properties peculiar to the infective bacterium and the host. Exposure (infectious) dose and serotype are just two important properties of the infective bacterium. Host factors would include age of the animal, nutrition, gestation and parturition, overstocking, transportation, concurrent diseases or other infections, and exposure to or treatment with antibiotics. When introduced into a naive herd, salmonellosis may appear as any one of the described syndromes. For example, an outbreak of salmonellosis due to S. dublin infection was investigated in a naive herd. Initially, calves and cows exhibited signs of respiratory disease and died acutely without evidence of diarrheal disease. Subsequently, a small number of pregnant cows aborted, had high rectal temperatures (105 to106 degrees F), and had profuse mucohemorrhagic diarrhea (mucus, blood and shreds of intestinal mucosa in their feces). Some calves and cows developed profuse mucohemorrhagic diarrhea, high fevers (105 to106 degrees F) for a few days, inappetence, depression, and very poor milk production. A small number of these affected animals died. After a period of time, which allowed for the development of herd immunity and implementation of biosecurity measures, severity of salmonellosis declined. Although not evaluated in this particular herd, exposed cows would be expected to shed S. dublin in their milk and feces for some time. A few cows would remain chronic carriers. Another previously uninfected herd was contaminated with S. infantis. There was no clinical evidence of salmonellosis in adult cows. The calves had low grade fevers (103 to 104 degrees F) and diarrhea that contained blood and mucus. The calves continued to eat and grow reasonably well. However, a few calves continued to shed S. infantis after being mixed in with older calves. The shedding calves contaminated the previously unexposed older calves, some of which developed diarrhea and required therapeutic intervention. During the past 2 years we have recorded the occurrence of salmonellosis in a number of Michigan dairy herds, where the disease occurred as a mild -to- moderately severe diarrheal
4 MICHIGAN DAIRY REVIEW disease that was accompanied by a high frequency of ketosis and left displaced abomasum (LDA) in affected cattle. Because of the mild diarrhea and the high frequency of ketosis and LDAs, salmonellosis was not originally considered in the disease process. However, the majority of affected cattle had high rectal temperatures (104 to106 degrees F), indicating some infectious process was contributing to the occurrence of ketosis and LDAs. From these scenarios it is apparent that Salmonella serotype, herd immunity, condition of the environment, and stress level play important roles in the herd’s response to exposure to Salmonella. Goals of Therapy Because Salmonella serotypes are associated with a variety of disease syndromes, treatment is often symptomatic. The first goal of therapy is to rehydrate and replace lost electrolytes in the affected animal. Anti-inflammatory agents and antibiotics should be administered if the animal has a high fever and appears septic. Due to the intracellular location of Salmonella, specific antibiotics at high concentrations are required. Antibiotics should be administered strictly on the recommendation of a veterinarian. In endemic herds, administration of an inappropriate antibiotic can cause salmonellosis in carrier animals that previously appeared healthy. Additionally, inappropriate use of antibiotics may prolong the carrier state and may lead to an endemic resistance problem on the farm. Salmonella serotypes rapidly develop resistance to various antibiotics. Lastly, because the metabolism of some cows may be altered and higher doses of certain antibiotics are required, extended withdrawal times will be necessary for some antibiotics. Carefully plan a therapeutic regimen with your veterinarian for the use of antibiotics when salmonellosis is occurring. Expect some treatment failures particularly in severe acute cases, and when an inappropriate therapeutic regimen is used. Tips for Detection When dealing with salmonellosis, the rate of new infections correlate with the degree of environmental contamination. Salmonella persists on a farm or in a herd because of its continuous excretion by carrier cattle and by its ability to survive in the environment for extended periods. Carrier cattle DO NOT exhibit any evidence of the disease, but transmit infective bacteria to other susceptible animals. The carrier state usually refers to adult cattle, as calves tend to clear the infection over time. However, calves may be nonclinical shedders for a few months after clinical signs of disease have disappeared. Salmonella may reside in colonic (large intestine) contents of calves for some time during and after convalescence. Three types of carriers have been described: active carriers, latent carriers, and passive carriers. Active carriers tend to
AUGUST 1999 be adult cows that have recovered from clinical salmonellosis. These active carriers may excrete Salmonella for years, particularly during periods of stress. Latent carriers carry Salmonella in tissues such as lymph nodes, and usually do not excrete Salmonella in feces until stressed. Passive carriers pass the bacterium through their intestinal tract into feces without invasion of the bacterium into the intestinal mucosa or lymph nodes. Passive carriers stop shedding Salmonella when removed from a contaminated environment. For an appropriate diagnostic evaluation, consult with your veterinarian who has direct access to the Animal Health Diagnostic Laboratory at Michigan State University. It is best to culture the bacterium from feces in live animals. Two to 5 grams of fresh feces should be collected directly from the rectum, placed into sterile containers and submitted to a diagnostic laboratory for culturing. When systemic disease is suspected, feces and blood should be cultured. Aborted fetuses should be submitted for diagnostic examination. At necropsy, suspect tissues should be collected and placed into sterile containers. Feces, tissues, and body fluids from dead animals should be cultured. Necropsy tissues should not be placed in unclean containers or contaminated during collection. For implementation of control measures, the cows’ environment should be examined for Salmonella. Sick cow and maternity stalls, loafing areas, water troughs, feed bunks, feed storage areas, and feed mixing equipment should be cultured. Biosecurity Measures In recent years, dairy herd expansions in Michigan have led to an increased percentage of herds with salmonellosis. In 1992-1993, we examined 70 herds for Salmonella serotypes and we found clinical salmonellosis among cattle in 14% of the herds. In 1997-1998, 44 herds were screened for salmonellosis, and we found clinical salmonellosis in 54% of the herds. Under conditions of expansion, a particular serotype may predominate in farms and in regions. After introduction into a farm Salmonella can become established rapidly, then spread to other farms. Biosecurity measures should be in place to prevent introduction of Salmonella onto the premises. When introduced into a herd, measures should be in place to help control the disease. First, it is important to recognize common sources for herd or farm exposure. Because all infected carrier cattle can not be identified, the risk of transmission onto a farm is high from carrier cattle. Other sources include visitors to the farm, farm personnel (particularly those individuals working on multiple farms), contaminated feeds and farm materials (seeds, fertilizers, and farm equipment), delivery trucks, shared farm equipment, birds, feral animals, and wildlife. As can be seen, Salmonella can be introduced onto a farm or into a herd by many different sources. Purchasing cattle from high risk farms, dealer farms, and sale barns in endemic regions should be avoided. Cattle are stressed by transportation, overstocking, and by unfavorable environmental condi-
MICHIGAN DAIRY REVIEW 5
tions that occur enroute to and in sale barns. A fair number of cattle originating from dealer farms and sale barns will be contaminated with Salmonella, shed Salmonella, or develop salmonellosis. For herds undergoing expansion, and if the herd of destination is a naive herd, cattle should not be purchased from facilities where a variety of animals from a number of different sources have been commingled. Purchase animals directly from the farm of origin, thereby avoiding sale barns, dealer barns, and other “at risk” facilities. As best as possible, assess the Salmonella status of the farm of origin. Use your own vehicles to transport new animals to an isolation facility on your farm. If contract haulers are used, provide an incentive for them to vigorously sanitize their vehicles and equipment prior to hauling your cattle. Insist that your cattle be delivered directly to your isolation facility in as short a time as possible. When salmonellosis is expected or diagnosed, it is critically important to identify and isolate infected animals, and prevent the spread of Salmonella in the farm environment. The main sources for Salmonella exposure in herds are sickcow stalls, maternity stalls, contaminated feed materials, and contaminated water. Controlling Salmonella begins by reducing the size of the infective dose by physically cleaning and chemically sanitizing all reasonable contact areas. This will include water troughs, feed preparation areas, and give particular attention to sick cow stalls, maternity stalls, and areas where sick cows are allowed to loaf. Isolate diarrheic animals away from all healthy animals, and away from human and equipment traffic. Assign responsibility for sick animal care to one or two individuals in order to limit human exposure and to limit human traffic in and out of the contaminated area. Designate equipment for use in the contaminated area only. Do not use equipment in the contaminated area and then use it to haul and mix feeds. Identify stressors such as overcrowding and reduce stress among the healthy animals. Provide proper clothing and shoe covers for workers and visitors to the farm. When possible and where practical have foot baths available for people. Accumulation of organic material in foot baths will inactivate disinfectants. Foot baths have to be cleaned on a regular basis to be effective. Disposal of carcasses, contaminated bedding, and manure may create major problems. Carcasses should be incinerated or buried deep to avoid exposing feral animals and wildlife. Contaminated bedding may be burned (check with local authorities about ordinances dealing with open air fires) or
composted. The compost area should be designed to restrict wildlife and feral animals. Open flush systems using recycled effluent water, spreading of contaminated manure and slurry require unique plans for controlling Salmonella. In herds contaminated with Salmonella and undergoing expansion, precautions have to be exercised when bringing in naive heifers or cows. There is the (strong) possibility that the new or naive animals may not have been exposed to the Salmonella serotype circulating in the herd. These naive animals will lack protective antibodies to the resident Salmonella serotype. If the naive cattle are exposed to the resident Salmonella serotype, the naive cattle may develop severe clinical salmonellosis. Calves born to the naive cattle will experience a much higher incidence and severity of salmonellosis when compared with calves born to resident cattle. Human Health Concerns The increasing prevalence of Salmonella in food animal production has brought about political and consumer pressures on livestock industries to control Salmonella. Apart from humans contracting salmonellosis through foods of animal origin, there has been much concern about infections with antibiotic resistant Salmonella. Multiple drug resistant S. typhimurium definitive type 104 (DT 104) has been recognized in Europe for some time as a human health pathogen. However, in the United States, the first documented cases of human exposure occurred in Nebraska in 1996. Another outbreak occurred on a Vermont farm in 1997. This isolated outbreak (published in U.S. News and World Report) received worldwide attention and focused attention on the emerging nature of this bacterium in the United States. Salmonella typhimurium DT 104 has been diagnosed in Michigan dairy farms. Simply stated, all Salmonella serotypes of animal origin are capable of causing disease in humans. Certain serotypes are more virulent than others, therefore, the degree of disease humans may experience after exposure will vary. An infected cow or calf undergoing an active infection will shed large numbers of Salmonella into the environment from their bodily excretions and secretions (feces, milk, and saliva). These animals and their environments are contaminated. Farm personnel and their family members undergoing chemotherapy, immunosuppressive therapy, are immunosuppressed by other means, or have chronic debilitating diseases, should not come into contact with Salmonella.
Stress and Immunity in Cows at Calving Jeanne Burton, Mara Preisler, and PattyWeber Dept. of Animal Science
he immune systems of cows at calving do not work to their optimum capacity, and this leaves cows highly
susceptible to bacterial diseases such as mastitis. Mastitis is inflammation of the mammary gland caused by diverse populations of environmental and contagious bacteria (4). The cow’s first line of immune defense against mastitiscausing bacteria is the neutrophil, a
white blood cell that moves rapidly from the circulation into the mammary gland in response to infection. If blood neutrophils do not migrate into an infected mammary quarter, bacteria can continue to multiply and cause severe inflammation that can permanently damage the
6 MICHIGAN DAIRY REVIEW milk secretory tissue. Although an elevated milk somatic cell count indicates mastitis, it also indicates that neutrophils have migrated successfully into the gland to fight bacteria. The neutrophil count in blood is a good indicator of an animal’s ability to fight bacterial infections. Neutrophils are produced by bone marrow and are continually released into blood. Neutrophils stay in blood for only 1 to 2 days before migrating to their primary site of defense in peripheral tissues. This keeps blood neutrophil counts relatively constant in normal, healthy animals. Abnormal blood neutrophil counts can occur if bone marrow output or trafficking into peripheral tissues is affected. In both cases neutrophil counts are elevated above normal. This is called neutrophilia.
AUGUST 1999 consequence. However, if peripheral tissue becomes infected when an animal is stressed, neutrophils cannot be recruited into the tissue, and the animal is at high risk of developing clinical disease. The reason that this scenario is so important to dairy cows is because blood cortisol is elevated around calving. High levels of cortisol are needed by the uterus at calving and by the mammary gland to initiate milk secretion. At the same time, the cows are exposed continuously to environmental bacteria
tify the molecules used by blood neutrophils for migration. Two important protein molecules called CD62L and CD18 have been identified (1). The CD62L and CD18 molecules are encoded in an animal’s genetic code (DNA) and, under normal non-stressed conditions, produce surface proteins on neutrophils. The CD62L protein acts like a Velcro strip to slow down rapidly circulating neutrophils and allow contact with blood vessel walls. In this way, blood neutrophils can survey tissues for signs of infection. If no infection is detected, the neutrophils dislodge from the blood vessel by shedding a piece of their Velcro strip and continue traveling with the flow of blood to a new site. However, if neutrophils detect an infection the CD18 molecules act like super glue and help them chisel through the blood vessel wall gaining access to inNeutrophilia fected tissue. Neutrophilia occurs It is important to know if under two main scenarios cortisol affects expression of in cattle. In the first, bacthe CD62L and (or) CD18 terial infection sends siggenes in blood neutrophils benals to rapidly increase the cause this would readily exoutput of neutrophils from plain altered trafficking of the bone marrow. If the infeccells in cows at calving. Cortion is severe enough, tisol is a steroid hormone that bone marrow output of transmits its message to the neutrophils becomes Figure 1. Elevated blood cortisol around calving is associ- nucleus in the interior of the greater than neutrophil miated with activation of neutrophil cortisol receptors (observed cell where the DNA of genes gration into the infected as reduced receptor levels) and neutrophilia in dairy cows. is located. These genes have tissue, which increases (Adapted from 5). sites that are recognized and blood neutrophil counts. bound by cortisol receptors to This is a normal healthy either turn on or turn off their response to infection. Under the secfrom manure, bedding, dirt, and water. expression. For example, it seems likely ond scenario, when an animal is exposed This is why cows at calving are highly that cortisol receptors turn on genes in to a stressful situation, neutrophilia is susceptible to new intramammary infecthe mammary gland because high blood associated with increased susceptibility tions with 60% or more of all environcortisol concentrations at calving cause to bacterial infections. The brain sigmental mastitis cases occurring in the initiation of milk secretion (Figure 1). nals the adrenal gland to secrete large first few weeks after calving (4). In contrast, genes involved in neutroquantities of a hormone called cortisol. phil trafficking appear to be turned off Elevated blood cortisol causes neutroPrevention of Mastitis Studied by cortisol receptors because neutrophils phils to lose their ability to migrate from To help prevent mastitis around calvfrom cows at calving and from cortisolblood into tissue so the neutrophils in ing, immunobiologists are studying the treated cows have almost no detectable effect get “caught” in the circulation (2). molecular mechanisms responsible for CD62L on their surface (1, 3). These If the stressed animal does not have an altered neutrophil trafficking in calvingcows have neutrophilia and are highly infection, this cortisol-induced change stressed cows. The first step was to idensusceptible to mastitis (1). in neutrophil trafficking has no major
MICHIGAN DAIRY REVIEW 7
Due to the negative impact of cortisol on trafficking and migration, researchers feel that the neutrophil cortisol receptor might be an excellent target for development of novel mastitis preventatives for dairy cows around calving. To validate this approach, we have done experiments to see if neutrophil cortisol receptors are involved in neutrophilia at calving. To do this, blood from 13 cows was collected around calving to determine neutrophil counts and cortisol receptor levels (5). Blood cortisol also was measured. Results in Figure 1 demonstrate that calving dramatically increased blood cortisol, which was correlated with a profound reduction in cortisol receptor levels and neutrophilia. We concluded that neutrophil cortisol receptors become activated by cortisol around calving and that this prevents neutrophils from leaving the blood circulation. We also think that neutrophils of multiparous cows are affected longer than in first lactation
cows and associated with higher rates of early lactation mastitis and metabolic disorders (5). Although actual disease susceptibility trials have yet to be performed, our preliminary observations suggest that activated cortisol receptors indicate or cause susceptibility to disease in cows around calving. Nonetheless, rise is cortisol concentrations around the time of calving is a normal natural event.
underway to identify DNA markers of mastitis susceptibility within cortisol receptor genes of various cattle breeds. These research efforts may provide management tools to aid in the reduction of mastitis around calving and in early lactation. References 1. 2.
Current Research Underway Our current research is to determine 3. if activated cortisol receptors directly effect lost CD62L gene expression in neu- 4. trophils. If so, we shall have information that will allow us to develop new drugs to prevent receptor activation in 5. neutrophils around calving. We anticipate that such products will help prevent mastitis by blocking a key hormonal signal that prevents blood neutrophils from migrating into infected mammary glands. Experiments also are
Burton, J.L., et al. 1995. Am. J. Vet. Res. 56:997. Kehrli, M.E., et al. 1999. In: Advances in Veterinary Medicine Vol. 41: Veterinary Vaccines and Diagnostics. R.D. Schultz (ed.). Academic Press, New York. p. 61. Lee, E.K., et al. 1998. Am. J. Vet. Res. 59:37. National Mastitis Council. 1996. Current Concepts of Bovine Mastitis, Fourth Ed. The National Mastitis Council, Madison, WI 53704. Preisler, M.T., et al. 1999. Glucocorticoid receptor down-regulation in neutrophils of periparturient cows. Am. J. Vet. Res. (submitted).
Microorganisms of Importance in Raw Milk Elliot Ryser Dept. of Food Science and Human Nutrition
ilk is legally defined as the “lacteal secretion, practically free of colostrum, obtained by the complete milking of one or more cows” with parallel definitions also provided for milk from sheep and goats. However, from a microbiological perspective, milk can be viewed as a highly nutritious growth medium for beneficial organisms as well as numerous spoilage bacteria and microbial pathogens. Normal Milk Milk, as secreted by the cow, is free of microorganisms. However, since external contamination of the udder and teat surface leads to movement of a few organisms up the teat canal, aseptically drawn milk almost invariably contains low levels of bacteria, typically ranging from several hundred to a few thousand colony forming units per milliliter (CFU/ml). The diversity of these contaminants is quite limited and most commonly confined to micrococci, lactococci, and Corynebacterium bovis, the last of which is considered an uncommon cause of mastitis. Most subsequent contamination originates from contact with soil, bedding, manure, feed, milking
equipment and/or milk handlers. Hence, non-aseptically drawn milk usually contains a diverse group of bacteria capable of growing over a wide range of incubation temperatures. In the United States, the standard plate count (SPC) for raw milk from individual producers legally must not exceed 100,000 CFU/ml with commingled raw milk not exceeding 300,000 CFU/ml (6). However, many economically driven milk quality incentive programs have led to the consistent production of individual and commingled milks having SPC’s of less than 10,000 and 30,000 to 70,000 CFU/ ml, respectively. A wide variety of bacteria, yeasts and molds typically enters raw milk during milking, with bacteria predominating. Development of closed milking systems, bulk tank storage, efficient transport, and improved refrigeration have changed the naturally occurring bacterial flora of raw milk from predominantly gram-positive (i.e., lactic acid bacteria) to gram-negative (3). These latter organisms usually account for well over 90% of the bacterial population, which is primarily comprised of psychrotrophs (organisms that grow at refrigeration temperatures) and coliforms (gram-negative, lactose-fermenting bacteria). In one recent survey (1), pseudomonads represented 70 to 80% of all bacterial isolates with the remaining gram-negative psychrotrophs belonging to
8 MICHIGAN DAIRY REVIEW various species of Aeromonas, Achromobacter, Alcaligenes, Chromobacterium and Flavobacterium. Growth of these psychrotrophic bacteria in raw milk during cold storage along with the simultaneous production of various lipolytic and heat-stable proteolytic enzymes strongly contributes to spoilage, off-flavor development, and reduced cheese yield. However, some proteolysis of milk proteins during refrigerated storage can be beneficial in that growth and acid production by lactic acid bacteria starter cultures is subsequently enhanced during cheesemaking. Most of the remaining gram-negative organisms in raw milk belong to the family Enterobacteriaceae with the coliforms (i.e., non O157:H7 Escherichia coli, Enterobacter, Citrobacter and Klebsiella) predominating. In addition to being indicators of unsanitary milking conditions and possible enteric pathogens, coliform bacteria have been associated with various product quality defects including the development of unclean flavors and early gas production in cheese. Gram-positive organisms, which now generally comprise less than 10% of the total bacterial population of raw milk, are primarily confined to lactic acid bacteria and spore formers, both of which are environmental contaminants. The lactic acid bacteria found in milk include various species of Lactococcus, Leuconostoc and Lactobacillus. Many of these organisms are important as starter cultures in fermented dairy products and also play a critical role in the much sought after flavor development that occurs during ripening of cheeses prepared from raw milk. However, others including certain gas-producing strains of lactobacilli have been linked to bloating and subsequent cracking of cheese. According to Martin (2), aerobic spore-forming bacteria are present in virtually all raw milk, generally at levels less than1000 CFU/ ml. Bacillus species, primarily Bacillus licheniformis and Bacillus cereus, account for about 95% of these sporeformers. Given the heat resistance of these bacterial spores, the presence of Bacillus species, particularly B.cereus, which is psychrotrophic and capable of producing extracellular toxins, is becoming increasingly problematic as processors seek to further extend the shelf life of pasteurized milk. The remaining spore-forming bacteria found in raw milk are anaerobes belonging to the genus Clostridium. Two species of environmental origin, namely Clostridium tyrobutyricum and Clostridium butyricum, have been repeatedly linked to “late gas blowing” of Swiss-type cheeses. Eliminating this defect from such types of raw milk cheese is a major challenge for the dairy industry. Mastitic Milk Mastitis, defined as an inflamation of the mammary gland, can be classified as either clinical or subclinical based on whether the signs of illness are symptomatic (i.e., fever, swelling) or asympyomatic (i.e., more than 5 x 105 somatic cells, shedding of the causative agent in the milk). Most cases of mastitis result from bacterial infections with the organism
AUGUST 1999 entering the udder via the streak canal of the teat. Bacterial pathogens most commonly associated with mastitis and shed in mastitic milk include Staphylococcus aureus, streptococci, (S. agalactiae, S. dysgalactiae, S. uberis), coliforms (nonO157:H7 E. coli, C. freundii, Enterobacter, Klebsiella), Pseudomonas aeruginosa and Actinomyces pyogenes. Less commonly, Listeria monocytogenes, Mycoplasma bovis, coagulase-negative staphylococci, Mycobacterium bovis, Brucella abortus, Corynebacterium species and Coxiella burnetti, are shed in milk as a result of mastitis (5), with many of these animal pathogens also producing life-threatening illnesses in humans. Human Pathogens The presence of human pathogenic bacteria in raw milk continues to pose a major public health concern to the dairy industry (4). When raw milk commonly was consumed early this century, Salmonella typhi (typhoid fever) and Streptococcus pyogenes (scarlet fever) accounted for 65 to 95% of all milk-borne illnesses with the remainder traced to Corynebacterium diphtheriae (diphtheria) and Mycobacterium bovis (tuberculosis). Although the recent spread of M. bovis from infected deer herds to cattle in northern Michigan has prompted some renewed concerns regarding raw milk safety, modern-day pasteurization and herd management practices have, for all practical purposes, eliminated these public health risks. Those bacterial pathogens common before World War II have been largely replaced by organisms of more immediate concern such as B. cereus (gastroenteritis), Brucella abortus (undulant fever), Campylobacter jejuni (gastroenteritis), enterotoxigenic E. coli (traveler’s diarrhea), enteroinvasive E. coli (dysentary), E. coli O157:H7 (hemorrhagic colitis and hemolytic uremic syndrome with a mortality rate of 3 to 10%), L. monocytogenes (perinatal septicemia, meningitis and abortion with a mortality rate of approximately 30%), Salmonella (gastroenteritis), S. aureus (emetic intoxication), and Yersinia enterocolitica (gastroenteritis and appendicitis-like abdominal pain). Two of these pathogens, L. monocytogenes and E. coli O157:H7, are particularly problematic with the former present in approximately 4% of the raw milk supply and linked to several outbreaks involving soft Hispanic or surface ripened cheeses. The latter has been responsible for over 60 cases of hemorrhagic colitis and several cases of hemolytic uremic syndrome that were traced to consumption of raw milk. Additionally, a recent sharp upsurge in the number of brucellosis cases reported along the Texas - Mexico border was traced to certain types of soft, unripened Hispanic cheese (i.e., Queso blanco) produced in Mexico from raw milk and illegally imported. While these aforementioned human pathogens easily account for over 95% of all dairy-related illnesses, the list of pathogens continues to evolve. Additions include Cryptosporidium (a parasite causing gastroenteritis), Salmonella typhimurium DT104 (a newly emerging multi-
MICHIGAN DAIRY REVIEW 9
antibiotic resistant strain) and Streptococcus zooepidemicus (15 cases and 1 fatality traced to Queso blanco cheese prepared from raw milk). Continued improvements in microbial isolation and detection techniques coupled with an aging population and more refined investigative strategies for milk-borne outbreaks undoubtedly will lead to the identification of additional opportunistic food-borne pathogens.
References 1. 2. 3. 4.
Celestino, E.L., et al. 1996. Aust. J. Dairy Technol. 51:59. Martin, J.H. 1981. J. Dairy. Sci. 64:149. Muir, D.D. 1996. J. Soc. Dairy Technol. 49:24. Ryser, E.T. 1998. In: Applied Dairy Microbiology. Marcel Dekker, New York, p. 263. 5. Weimer, P.J. 1998. In: Applied Dairy Microbiology. Marcel Dekker, New York, p. 1. 6. White, C.H. 1998. In: Applied Dairy Microbiology. Marcel Dekker, New York, p. 431.
Business and Finance
1998 Business Analysis of Michigan Dairy Farms Sherrill B. Nott Dept. of Agricultural Economics
his article provides information from 141 dairy farms in Michigan that completed a financial business analysis with Michigan State University’s Department of Agricultural Economics. To be in this group, 50 percent or more of gross cash income had to come from a combination of milk and dairy animal sales. On average, these combined items were 93 percent of total cash income. All factors were calculated with software from the University of Minnesota’s Center for Farm Financial Management. Milk Sales The 141 farms had an average of 192 cows, sold 20,910 pounds of milk per cow, and received the gross price of $15.27 per hundred weight (cwt) of milk sold. This is $1.53 more than the average price received in 1997 by a similar group of farms. Individual milk prices among farms ranged from $13.00 to nearly $19.00 per cwt. Although breed differences may account for some of the variation, quality incentives and protein premiums also played a part. Butterfat price differentials were higher in 1998 causing more of the farm-to-farm price differences than in previous years. The farms cropped an average of 558 acres, 333 being owned. The rest were cash rented. This is an average of 2.9 crop acres per cow. Three farms grew none of their feed, whereas some had major cash cropping enterprises in
addition to dairy. The average farm had $13,188 of cash crop sales, with corn, soybeans, and winter wheat having the largest amounts. Average Yields per Acre Reported average yields per acre in 1998 were 112 bushels of corn, 3.9 tons of alfalfa hay, 13.9 tons of corn silage, and 46 bushels of winter wheat. In 1997, the average yields for a similar group of farms were 106, 5.0, 16.2, and 62 for corn, alfalfa hay, corn silage, and winter wheat, respectively. Drought was a negative factor in northern Michigan in 1998. Net cash farm income (gross cash income minus cash expenses minus interest paid) was $137,400 per farm. This cash difference had to cover family living and principal payments, assuming capital purchases were financed with debt. Net farm income averaged $114,100 in 1998 compared with $55,000 in 1997. Going from net cash to net farm income involves accrual adjustments for inventory change and depreciation. Depreciation and other capital adjustments, including change in value of the dairy herd, was a negative $48,600 in 1998. Inventory changes, mostly of feed and prepaid supplies, was a plus $25,300 on the average farm. Feed Inventory Changes Feed inventory changes are where, in financial documents, one can see the impact of yield and price changes. For a group of similar farms in 1997, feed inventories increased $24,740. For the
141 farms in 1998, feed inventories increased an average of $4,480. Prices of farm produced crops were mostly lower at the end than they were at the beginning of 1998. Purchased feed per cow was $841 in 1998, down from $878 in 1997. Milk sold per cow was only 2 pounds higher in 1998 than in 1997. Net Worth Increases Cited Net worth change, like net farm income, is a good indicator of business success during the year. The 141 farms had an average increase in net worth of $76,600 using a cost basis balance sheet. Using the market value balance sheet, where all assets are valued at what their estimated prices would be if sold, the same farms averaged a $121,400 increase in net worth. This includes nonfarm assets. However, nonfarm assets made up just over 5 percent of total assets. The market value change reflects land prices, which have been increasing during recent years. Land values in a cost basis balance sheet would not change during the year unless land was bought or sold. Many farms also increased their milk cow values per head at the end of 1998. From the market value balance sheet, debt on this group of farms was 34 percent of assets. Equity was 66 percent, which is about the same as all farms throughout the country. Farm debt averaged $2,679 per cow at the end of 1998. This is an acceptably strong financial situation in which to be. However, the debt flows during the year
10 MICHIGAN DAIRY REVIEW might be of concern. The average farm borrowed $175,800 of principal during 1998. The average farm made $142,100 of principal repayments, meaning debt increased about $33,700. Each day of 1998 saw the average of these 141 farms getting $92 deeper in debt. However, I’ve already indicated that net worth increased, so management must have increased assets faster than debt. Unpaid Labor Returns Positive With net farm income being positive, return to unpaid labor of the owners and managers was positive. They earned $22.25 per hour of unpaid labor. That’s more than triple the current minimum wage. The previous year owners earned $11.26 per hour on a similar group of farms. People often ask what’s the difference between high income and low
income farms. The software I used lets me average results for the 25 percent of farms with the highest, and for the 25 percent of farms with the lowest, net farm income. Remember, this measure is after accrual adjustments for inventory change and depreciation. Net farm income was $299,500; $114,100; and $300 for the high 25 percent, the whole group’s average, and the low 25 percent, respectively. The computed results don’t help much in explaining why the high income farms are high and the low income farms are low. The low 25 percent actually received 13 cents more per cwt for milk. The number of cows was 349, 192, and 131; milk sold per cow was 22,266; 20,910; and 18,657 pounds, respectively, for the high, average, and low income farms. This indicates size and production might have been associated with higher net incomes. One of the more telling
factors is total expense as a percent of income. It averaged 77 percent, 80 percent, and 88 percent for the high, average, and low income farms, respectively. Total farm debt per cow was $2,285; $2,679; and $3,540 for the high, average, and low income farms, respectively. This means higher cash interest is part of the reason for the higher expense levels on low profit farms. Location of Farms The 141 farms in this study were located throughout 47 counties in Michigan. They ranged from the Keweenaw Peninsula to the shore of Lake Erie. Most farms kept their financial records in systems supervised by MSU Extension, Farm Credit Services, or AgriSolutions. These farms are much larger, and probably better managed, than would be the average of all dairy farms in the state.
Reproduction and Facilities
Is Your Farm Equipped for Reproductive Success? Roy Fogwell Dept. of Animal Science
hen you think of equipment for reproductive success you probably consider: insemination guns, plastic sleeves, storage tanks for semen, and identification for cattle. This list is correct but incomplete. A complete tool box for reproductive success must include “handling facilities” to sort and restrain individual heifers and cows. A purpose of handling facilities for cattle is to insure that other tools and techniques can be used effectively on individual heifers or cows. Consider these questions to evaluate the effectiveness of your facilities to handle individual animals. • Do you have facilities designed to sort and restrain individual animals? • Do your current facilities help you achieve your goals for reproductive success? Or, are there activities that do not occur because they are too difficult or require too much time? • Do your current facilities use people effectively to achieve reproductive success in your herd? Or, do you consume time chasing animals instead of completing tasks? Are multiple people required to inseminate one heifer or cow? • Do your current facilities produce accomplishments from
routine and proactive efforts? Or, is your reproductive program mostly reactions to a list of urgent or unfinished jobs? • Do your current facilities assure the safety of people and animals? Or, is there high risk to injure an animal or are you at risk of liability for a personal injury claim? The ability for you to sort and restrain heifers and cows will affect reproductive success. For example, in 1980 we demonstrated synchronization of estrus in heifers in about 40 dairy herds in Michigan. Early in the project we encouraged cooperators to establish a facility to sort and restrain heifers to inject prostaglandin, for artificial insemination (AI), and for fertility exams. After 3 years, continued use of AI in those herds depended on presence of an effective handling facility. Presence and use of facilities to sort and restrain cattle is key to achieving your goals for reproductive management. Reproductive management includes but is not limited to AI with correct timing and technique. In fact, management that supports reproductive success requires numerous actions at specific times to individual animals throughout their lives. With a facility that is planned to sort and restrain individual animals, actions needed for reproductive management will be efficient, convenient, timely, safe, and are much more likely to be completed successfully.
AUGUST 1999 Reproductive success varies widely among dairy herds and is accomplished by divergent styles of management. When reproductive success is not optimal it is usually because activities are not completed and the work that is performed lacks quality. A facility to sort and restrain animals is a tool that can correct both of these limitations to management. For this discussion it is assumed that most dairy managers know what must be done to achieve reproductive success. Thus, amount of knowledge is usually not limiting to your success. Do your facilities limit your ability or opportunity to use your knowledge fully, to execute a management plan, and to complete all tasks required? By definition, a task is difficult or unpleasant work. This view of work is negative and is likely to exist when handling facilities for reproductive management of cattle are absent or not adequate. In contrast, when thoughtful and effective facilities are present for heifers and cows, those jobs that could be tasks now will be accomplishments from routine and proactive activity. A large portion of reproductive success requires that actions are taken at specific times with close attention to technical details and biological rules. A facility to sort and restrain heifers and cows will assure that actions are completed, that the quality of work is excellent, and that your labor is used efficiently. Just a partial list of actions needed to achieve reproductive success will illustrate that major commitment and much effort are required, and these demands could be overwhelming. When activities for reproductive management are not accomplished fully reproductive success will be reduced. If there is an effective handling facility, activities will be completed with attention to: safety, quality of work, efficiency of labor, proper scheduling of animals, and a positive effect on reproductive success. What Tasks Require Cattle to be Sorted and Restrained? To realize the need for handling facilities you should consider a list of all activities and accomplishments that are necessary with individual animals so that your herd achieves reproductive success. Health practices for heifers and for cows are necessary to prevent and to treat problems. Major activities are vaccinations and deworming. But you should also review capacity and quality of the maternity area because health around calving is important to reproductive success. Body condition scores are used commonly to monitor nutritional welfare of heifers and cows. For heifers, it is ideal to schedule conception at a particular body weight, withers height, and body condition score. These indicators of nutritional sufficiency and growth are best measured when animals are restrained. For heifers and cows, there are numerous programs to synchronize heat that require injections or implants. It certainly is easy and effective to inject animals that are restrained. Any program for AI of heifers or cows requires an area to observe animals for heat and to sort and restrain individual
MICHIGAN DAIRY REVIEW 11 animals for AI. If bulls are used, there must be a facility to limit access to only those heifers or cows that are in a breeding group. Females must be sorted and restrained for fertility exams to determine which animals are not pregnant. Furthermore, as the status of animals changes with growth, yield of milk, pregnancy, or health it is necessary to sort individuals or to establish new groups. The tasks required for reproductive management are numerous and diverse. Thus, a facility must be planned carefully to accomplish and to enhance all aspects of management necessary for reproductive success. What to Include in a Handling Facility? Proper gates should allow you to sort safely an individual animal from a group and to move sorted animals easily to a facility for restraint (1). Restraint should be safe for animals and people. The level of restraint must be adequate so the planned activity is accomplished efficiently and effectively. For example, passing an AI gun through the cervix of a female restrained in a squeeze chute will be easier and more successful than when a female is haltered to a post or wedged into a freestall. A handling facility should be available for use 24 hours every day (1). The facility should allow access to the neck, rump, ribs, or rectum as required for the intended task. In the future, intramuscular injections may be allowed only in the neck or other low value areas. This potential policy about sites for injections will affect the type of restraint that will give acceptable results. Identification of animals for insemination or treatment must be accurate and convenient. For example, for animals with ear tags and restrained in “gang lock” stanchions, one person must be outside of the pen in front of the animals to confirm identity. Changing the system to identify animals may make your handling facility more efficient and identification will be more accurate. Special equipment or supplies that are needed at the facility will be determined by the activities planned. For example, semen should be stored close to the facility where AI occurs because semen should be deposited within 10 minutes after thawing. If semen is thawed at the handling facility there should be a source of hot water. Some hormones and biological supplies used at a handling facility may need refrigeration. Because of financial value or potential hazard to safety, storage may need special attention to security. Finally, the equipment and facility should be planned to insure regular and effective cleaning. Because a major reason for a handling facility is to increase efficiency of labor, it is important to consider the number of people available or required to perform the activities needed. If your goal is that most or all activities can occur with one person, the design and equipment installed must consider this goal. A facility to handle heifers and cows should allow rapid completion of activities to minimize the amount of time that
12 MICHIGAN DAIRY REVIEW animals, especially lactating cows, are separated from feed and water. Facility Locations to Sort and Restrain Three major options exist for the location of a facility to sort and restrain dairy cattle: milking center, freestall barn, or a separate facility dedicated to sort and restrain animals (1). The milking center is a common choice because many of the features needed to handle cattle already are present. But, using the milking parlor itself for a handling facility is not a good choice for people or for animals, especially heifers. In addition, the milking parlor is frequently not available when you need to restrain animals. Note that if your parlor is available frequently for non-milking activities, the parlor is too big for your herd! But, sorting gates with a working chute or “management or palpation rails” placed adjacent to the return lanes from the parlor will provide an opportunity for a handling facility within the milking center but will avoid use of the parlor (2). Another possible location for a facility to handle cattle is within the freestall barn. Restraint can be achieved with “gang lock” stanchions or a squeeze chute placed in a cross alley. To use cross alleys, there must be gates to sort and to direct the cattle to the chute. In addition, there is the challenge to insure that this facility and the associated gates do not interfere with routine management activities such as feeding, cleaning alleys, or moving animals for milking. Be sure to include convenient and secure storage for supplies and equipment. A third option is to establish a separate facility that is dedicated to sort and restrain animals for management activities. A dedicated facility could be an S-shaped alley with a squeeze chute and pens for sorted animals. Alternatively, a dedicated facility could be a section of “gang lock” stanchions or tie stalls separate from the milking center and the area for housing. Finally, a dedicated facility to sort and restrain animals could use the relatively new “management or palpation rails” (3). Consider Separate Facilities for Cows and Heifers During your review of handling facilities, you really should consider a facility for cows and a separate facility for heifers. Two facilities are needed because heifers are smaller than cows and heifers are typically in a different location from cows. In addition, a separate handling facility for heifers and for cows will insure convenient location and allow you to pursue the intense management necessary for both types of animals to have reproductive success. If you only have a facility for your cows and none for your heifers, this is a major void in your tool box. Which of these or other choices is best for you must be guided by the arrangement and design of your current barns, general routes to move cattle, and by your list of activities to be performed. For example, if you need very light restraint to score body condition, “management rails” would be adequate.
AUGUST 1999 But, if you need more firm restraint to inseminate or palpate one cow, a squeeze chute may be the best choice. Be sure that your facility is designed and located so you can complete your list of activities and to fulfill your management plan. Work to avoid the situation where the facility dictates and limits the management plan and thus limits reproductive success. Develop a management plan for reproductive success and then establish a handling facility that will allow you to execute all aspects of your plan. Summary So why does your dairy farm need a facility to sort and restrain cattle? Firstly, a proper facility will insure that activities are completed on time, that accomplishments have high quality, and that labor will be efficient. Secondly, veterinarians may charge less when good facilities allow them to be effective and more efficient. Third, good facilities will ease adoption and enhance success of technologies. For example, numerous technologies including bST and synchronization of heat or ovulation require multiple injections so restraint of animals is critical. Although AI is not new, this technology is not used in all farms or in all females. Especially with heifers, a major reason AI is not used is because there are no facilities to sort and restrain individuals for insemination. Every dairy farm is different in facilities, expertise, number of people, and goals for reproduction. So, there is no best design or ideal location for a facility to sort and to restrain cattle. For general ideas and specific designs you should review the publication, Dairy Freestall Housing and Equipment, from the MidWest Plan Service or contact Monsanto about “management rails” (see references). But, a first step is that you must evaluate whether or not your current facilities to sort and restrain animals could be improved. A motivation or incentive to review and renovate facilities is because you see opportunity to increase convenience or to increase the quality of reproductive management on your farm. Facilities are almost always the first limiting factor to execute an aggressive management plan for reproductive success. In addition, proper facilities can increase safety and thus will reduce your liability if someone is injured. If you are not convinced by your economics, facilities to handle cattle can be justified strictly as a convenience. But, a handling facility, though convenient, is necessary for reproductive success and thus is not a luxury! Finally, to establish effective facilities to sort and to restrain cows and heifers is an important investment for your management tool box. Investment in facilities, like investing in reproductive success, will not generate visible financial returns immediately. Facilities are an investment for the long term. If you are committed to manage for reproductive success, effective handling facilities will be used extensively and loved by all people at your farm. Be sure that your farm is equipped for reproductive success!
MICHIGAN DAIRY REVIEW 13
References 1. 2.
Bickert, W. G. 1998. Proc. Fourth International Dairy Housing Conference. ASAE Publication 01-98, St. Joseph, MO. MidWest Plan Service. 1997. Dairy Freestall Housing and Equipment. Sixth Ed. To order, send check for $22.00, payable to
Michigan State University to Plan Service Secretary, 217 Farrall Hall, Agricultural Engineering Department, Michigan State University, East Lansing, MI 48824. Management Rails. 1998. Scoop- A Newsletter from Monsanto Dairy Business. Vol. 2 (3) or call 1-800-233-2999.
You Can’t Take Them Off, Until You Put Them On Dean Ross Extension Dairy Agent Ingham, Jackson, Livingston Macomb, Oakland,Washtenaw and Wayne Counties
variety of issues involved directly with the act of removing milk from the udder can have a huge impact on the efficiency, health, and profitability of dairying. Once the cow’s udder has been stimulated, sanitized, and dried, the time has arrived to attach the milking unit. Attachment of the milking unit should occur within 1 minute of the start of stimulation of the udder. Planning and organization of milking routines for individual farms should be arranged to meet the 1 minute goal. Factors involved in this planning may include: number of units per milker, level of automation of the milking system, udder preparation routine, labor requirements of the milking facility, and level of labor efficiency. The Milk Ejection Reflex The reason for a 1 minute goal for attaching the milking unit is to take advantage of the oxytocin-induced milk ejection reflex. Manual stimulation of the teats during the sanitation phase of udder preparation causes the cow to release the hormone oxytocin into her blood stream. Oxytocin causes the alveoli in the udder to contract and force the milk, which has been previously produced and stored there, into the ductal system. If this rush of milk is not promptly removed from the udder, further release of milk is stopped. Maximum pressure in the
udder is reached at about 1 minute and lasts only about 5 minutes. The best use of the letdown mechanism is therefore gained by attaching the milking unit no later than the 1 minute post-stimulation (1). Minimize Vacuum Fluctuations The primary goal in attaching, adjusting, and removing the milking unit properly is to minimize vacuum fluctuations at the teat ends. Most properly designed milking systems should be able to provide enough reserve air flow to prevent vacuum fluctuation during recovery from having one or two milking units knocked off. Drastic changes in pressure at the teat ends due to air leaks or as they are commonly called, liner slips, also need to be minimized, particularly those slips near the end of milking caused by uneven milkout or transient changes in udder size and shape. Proper attachment of the milking unit is key to successfully milking the cow. First, the unit must be supported level in one hand to minimize air leakage during attachment. The teat cups dangling down evenly on each side of the claw will help seal-off the claw from air leaks during attachment. Grasp the outer end of the teat cup between the thumb and middle finger, and kink the tube portion of the inflation as the teat cup is positioned beneath the teat. If the inflation remains kinked little or no air should pass. The index finger can be used to locate the teat end and guide the mouth of the teat cup onto the teat. When the teat cup is positioned it can be seated onto the teat.
Adjust Your Milking Unit When the milking unit is attached firmly to all four teats, it should be adjusted in order to level the claw and provide even, downward pressure on each teat. As milking proceeds, some cows and certain quarters will milk faster than others. This requires the milker to be vigilant and the organization of the milking routine must allow the milker time to observe and adjust milking units as needed. Situations where the milker has other tasks, for example, moving cows outside the milking area do not provide the milker the time to adjust and (or) remove milking units as they require service. Improperly aligned milking units can lead to uneven milkout, and more liner slippage. Avoid Liner Slips Because all cows are not created equal, not all quarters milk out at the same rate. Fast milking quarters may allow air to slip past the empty teat into the milking unit. These “liner slips” should be avoided. They have been implicated as a route for spread of mastitis in dairy cattle. As air leaks into the liner around the teat end, vacuum in the other three teat cups reverses momentarily and forcibly blows air at those teat ends. Mastitis-causing organisms usually are present in the small milk droplets carried by that air, and literally can be driven up into the teat canal. This is a common route for diagonal quarter infections. Additionally, if cows with chronic subclinical mastitis are not separated from the milking herd, they may spread organ-
14 MICHIGAN DAIRY REVIEW isms by leaving behind residual amounts of infected milk in the inflation that can infect animals milked after them during a liner slip. Udder Inspection Important The vacuum in the milking unit must be shut off prior to removal of the teat cup at the completion of milking. Failure to do so can lead to liner slippage and teat end trauma. Situations where vacuum is turned off manually require the milking unit be gently pulled off to release the vacuum in the claw or waiting until the vacuum inside the claw decreases before pulling the machine off. Systems with automatic take offs will turn the vacuum off prior to removal. Once the machine is removed, the udder should be inspected to determine that it has been milked out completely. This
inspection is done ideally before removing the machine. Unfortunately, many new parlors are not organized to provide time for inspection before milking unit removal. The machine can be placed back on the udder if required, but care must be taken that the cow is not regularly and extensively over milked. Most teat injury and subsequent infection happens at the end of milking (2). Over-milking can cause teat lesions, and teat congestion. Still, slightly overmilking the cow is preferable to undermilking. In parlors with automatic detachers, a flow rate of 1 lb per minute or higher with a delay time of less than 5 sec should be set.
unit. Proper milkout of the cow is essential for maximizing the flow of milk, but also is a key to preserving udder health. The act of milking is an important, but often overlooked activity on dairies across the country. It is well worth the time and effort to develop a consistent milking routine. Doing so will increase production and decrease labor costs while improving udder health. References 1.
Use Germicidal Teat Dip Teats should be dipped in an effective germicidal teat dip as soon as possible after removal of the milking
National Mastitis Council. 1993. Recommended Milking Procedures. WWW: nmconline.org/info.htm. Milking Machine Manufacturers Council, 1993, Maximizing The Milk Harvest: A Guide for Milking Systems and Procedures, Page 9, Equipment Manufacturers Institute, Chicago.
Michigan Milk Market Update
Figure 1. Basic Formula Price, 1994-1999.
The $10.26/cwt in February is the low of 1999 with the BFP rebounding a bit to $11.81 in April. Cheese and butter prices suggested a stronger BFP to finish the summer. Michigan milk market prices for 1998-99 are displayed in Figure 2.
18 17 16 15 14 13 12 11 10
he average mailbox milk price in Michigan for 1998 was $14.84/cwt. This is up $1.91/cwt from the 1997 average of $12.93/cwt and $0.64/cwt from the 1996 average of $14.20/cwt. For all Federal milk orders the average mailbox milk price for those same years was $14.99/cwt (1998), $12.99/cwt (1997), and $14.28/cwt (1996). From these figures you can see that Michigan milk producers receive an average mailbox milk price just below the average in all Federal milk orders. Total milk sold to plants by Michigan producers totaled 5.33 billion pounds in 1998. This amount was down from 5.35 billion pounds in 1997. In 1998, U.S. milk production was 154.924 billion pounds while in 1997 U.S. milk production was 153.405 billion pounds. The result is that Michigan produced 3.44% of U.S. milk production in 1998, down from 3.49 percent in 1997.
Milk Prices The monthly basic formula price (BFP) since 1994 is displayed in Figure 1. The $7.07/cwt drop from December, 1998 to February, 1999 made even the $4.03/cwt drop from September to December 1996 look tame by comparison.
Christopher Wolf Dept. of Agricultural Economics
F.O. 40 Blend
Figure 2. 1998-99 milk prices and premium in Michigan.
4.5 4 3.5 3 2.5 2 1.5 1
These prices reflect the drop in manufactured milk price. The fluid milk premium peaked at $2.02/cwt in April which, to some extent, helped off-set the drop in fluid prices that occurred with a lag from the BFP drop in February. The average mailbox milk price divided by the feed prices in Michigan for 1997-1999 are displayed in Figure 3. The feed cost index is a function of the average Michigan prices of corn, hay, and soybeans. The milk price-to-feed cost ratio is a simple proxy for profitability. A higher ratio indicates a larger margin between milk and feed prices and should indicate that the average Michigan dairy farmer is better off than with a lower ratio. This ratio is a general barometer of the margin between milk price and feed prices. The ratio ranges from a low of 2.03 in May 1997 to a high of 4.09 in December 1998. As Figure 3 shows, the milk-to-feed price ratio, which had climbed steadily through 1997 and 1998 took a tumble in early 1999. While feed prices stay relatively constant at their low levels, the precipitous drop in milk price resulted in a smaller milk-feed price margin for Michigan dairy farmers.
MICHIGAN DAIRY REVIEW 15
Milk Price ($/cwt)
Figure 3. 1997-1999 milk-to-feed price ratio in Michigan.
Industry and University
Bill Thomas Named ADSA Fellow Pam Jahnke Dept. of Animal Science
ntrigued by the inner workings of nature has been a driving force of Michigan State University Emeritus Professor J. William Thomas’s half-century career. His curiosity has sparked renowned research, an ever-growing extension program, and successful graduate students. Dr. Thomas, 81, was named a Fellow of the American Dairy Science Association (ADSA) for his distinguished service to the dairy industry in June at the 94th annual ADSA meeting in Memphis, TN. A reception, which attracted colleagues, former students and friends gathered there to honor him and his wife, Carolyn. He is one of six persons to be named a Fellow in 1999 and only one of three MSU professors to have ever received the honor. The association annually awards the honor to a maximum of 0.2% of its membership. “It’s great to be considered worthy of the award by people you have associated with,” said the East Lansing resident, who
affectionately still is referred to as “Dr. T” by former students and can be seen visiting his Anthony Hall colleagues on a regular basis. At the beginning of his career he investigated the use of thyroprotein, and in his retirement - bovine somatotropin (bST), which today is used to increase efficiency of milk production in many dairy herds. His five-decade span of research activities produced results that were presented at ADSA meetings from 1947 through 1995. His research tackling all aspects of dairy nutrition including vitamins, minerals, compounds with hormonal activity, proteins, and energy sources often was in the forefront of the field. He has authored more than 400 publications including 143 peer-reviewed journal articles. Reflecting on the award, one of Dr. Thomas’s colleagues, MSU Professor Harlan Ritchie said, “Bill has one of the sharpest and most inquiring minds I have ever been around. No one knows scientific literature better than he does. I have always admired Bill’s range of expertise.”
16 MICHIGAN DAIRY REVIEW Another colleague, MSU Professor H. Allen Tucker said, “Bill never really retired. To this day he always has a science journal or farm magazine in his hand for reading. His wife Carolyn, his reading, his interest in solving farmers’ problems, and his skiing have kept him young.” Perhaps, Dr. Thomas’s career path was a natural given his agricultural roots. “I was reared on a small dairy farm,” he recalls, with “40-some odd acres” in Spanish Fork, Utah. Farm chores, which he shared with three younger brothers, and attending livestock shows consumed much of his time as a youth. Encouraged by judges (who were professors), he decided to pursue dairy and chemistry studies at what was then known as “Utah State College.” “I am intrigued by finding out how things work in nature what goes on inside animals and plants.” He graduated with his bachelor’s of science degree in dairy and chemistry in 1940 from Utah State University and his doctorate degree in biochemistry, physiology and animal nutrition in 1946 from Cornell University. Prior to being hired as a professor in the Departments of Dairy and Animal Science at MSU in 1960, he served as a nutritionist, biochemist, and dairy husbandman at the USDA Dairy Cattle Research Branch in Beltsville, MD. Research Results in Well-known Processes It was in Beltsville, where he began his research of galactagogues for lactating dairy cows. After retiring from MSU he supervised commercial farm trials with bST. These results formed part of the basis for the U.S. Food and Drug Administration approval of that product. At least three widely used processes are partially a result of Dr. Thomas’s research. They include: anhydrous ammoniation of corn silage, accelerated hay drying, and the use of dietary buffers and alkalizers to increase the production of milk fat. Dr. Thomas was among the first to use laboratory procedures to select strains of alfalfa with improved digestibility and nutritive value. Today the use of laboratory procedures to improve the nutritive value of crops is common practice. Inside the laboratory, he served as a mentor to many graduate students - especially when he was director of the MSU-National Institutes of Health, Nutrition Training Grant from 1968-81. A former colleague and retired MSU Professor, Roy Emery said, “We had a number of excellent Ph.D students graduate under that program, and Bill is seldom given the credit he deserves for spearheading that program.” Emery also is an ADSA Fellow. Although his career at MSU, which spanned from 1960 to 1987, entailed research, teaching and extension, he plays no favorites. Yet, he acknowledges that others view his extension service as perhaps his most meaningful. “I was visiting farms and talking to dairy producers to increase their knowledge and to answer their questions about
AUGUST 1999 practices, while providing some biological basis for maximizing milk yield and profitability.” During the last decade of his MSU career, his extension activity increased and he spent more time training county agents, visiting farms and investigating special farm problems such as polybrominated biphenyl (PBB) and phencyclidine (PCP). MSU Professor Ritchie recalled, “On numerous occasions, when I was stymied at solving a farmer’s problem, I would consult with Bill to help come up with the solution. Whenever I asked him to participate in an extension program dealing with ruminant nutrition, he willingly accepted.” Dr. Thomas also originated a shortcourse dairy program, along with a book comprising 40 articles for this class. One section dealt with a hand ration balancing program developed for the TI-59 hand calculator. This formed the basis for the first computer Spartan Ration Balancing Program (Spartan 1.0). Dr. Thomas’s travels also took him beyond Michigan to participate in several U.S. and international conferences. He presented papers on topics like “Forages, harvesting, storage and feeding processes” in Eastern Europe; taught courses on ruminant nutrition and feeding in Brazil, and consulted on dairy cattle and milk processing in Hanoi, Vietnam. Currently, he serves as a consultant for commercial agricultural companies and farmers in the Tri-State area, while remaining up-to-date with dairy nutrition research, and he continues to be in frequent contact with his colleagues. Throughout his career, Dr. Thomas has noticed gradual changes in the farming industry to consolidate the milk processing and milk producing industry with an increased size of operations and efficiency in both areas, thus requiring more knowledge among dairy workers. Though small family farms are not completely extinct - he has seen Amish farmers operate with 20 cows while supporting10 children - most farmers today don’t want that type of lifestyle. “Instead of the dairy as a lifestyle it has become a big business operation. You have to use a business mentality and procedures in order to operate successfully,” he recently said.
MSU Presents Strong Showing at Dairy Science Association Pam Jahnke Dept. of Animal Science
airy programs from Michigan State University were well represented at the 94th annual meeting of the American Dairy Science Association (ADSA) in June in Memphis, TN. Over 1,500 members met to exchange the latest in ideas, research, and trends of the dairy industry. About 25 MSU faculty, academic specialists, graduate students, and research assistants from the Animal Science and Food Science and Human Nutrition Departments presented their research in symposia and many short presentations and
AUGUST 1999 posters. A MSU Animal Science graduate student also won the Graduate Student Paper Competition. The ADSA is an international group of educators, scientists, and industrialists working to advance the dairy industry and develop new technologies to keep up with U.S. and global populations’ nutritional, health, and economic needs. MSU Representatives Present Varied Topics Topics presented by MSU representatives were among sessions in extension, education, nutrition, physiology, and dairy foods. Professor H. Allen Tucker presented a 41-year perspective on hormonal control of mammary growth and lactation. Despite all of science’s modern technology to achieve the highest milk-producing cows, Mother Nature still does it best, said Tucker. “The greatest physiological stimulus for milk yield is pregnancy, not some cocktail of injected hormones, growth factors, receptor agonists/antagonists, or gene therapies. Viva la mom!” In the Dairy Foods Division of the program, Associate Professor Zeynep Ustunol, Food Science and Human Nutrition Department and former graduate student Heather Vachon co-authored a paper, “Effect of sweetener type on lactic and acetic acid production by lactic acid bacteria and bifidobacteria in skim milk.” Substituting honey as a sweetener for fructose or sucrose in dairy products like yogurt was examined because of its ‘healthy’ and natural image. Lactic acid production by lactic acid-producing bacteria was not affected by different sweetners. However, with bifidobacteria lactic acid production from honey increased, likely as a result of the variety of oligosaccharides in honey. Professor David Beede spoke on meeting current and future challenges of a dynamic dairy industry in an ADSA symposium in extension education with co-authors Assistant Professor Miriam Weber and Dairy Specialist Joe Domecq. Maintaining up-to-date university programs to meet the needs of a dynamic dairy industry requires a strong and interactive partnership with industry, Beede said. “In Michigan, development of this partnership was catalyzed by the Michigan Animal Agriculture Initiative,” he said. Current and new technical research originating from industry input also fuels two- and four-year undergraduate teaching programs. Another paper, “Tri-State Dairy Nutrition Conference,” cited the importance of extension work. Professor Herb Bucholtz, a co-author of the abstract, said the conference is a yearly event for feed industry professionals who have direct contact with dairy producers. This conference serves an important role in attracting research and extension faculty from many different universities and industry professionals to meet the dairy industry’s research and educational needs. The function of follicles in the bovine ovary was the focus of another symposium. Professor James Ireland presented “Dominant follicle turnover: An overview.” Ireland discussed
MICHIGAN DAIRY REVIEW 17 hormonal regulation of growth of ovarian follicles during the estrous cycle in cattle. Future research needs were discussed to improve control of follicular development and fertility in the cow. Ireland said “the conference brought together leading animal scientists with expertises both in basic and applied research of ovarian function. These scientists shared ideas and presented new information on how follicle growth is regulated. These findings may prove useful to understand how ovulation can be better regulated in cattle.” Fertility also was the subject of another symposium presentation. Assistant Professor Richard Pursley spoke on, “The high producing dairy cow: Goddess of low fertility.” The presentation addressed the physiological differences between heifers and lactating cows that could be responsible for differences in fertility. “Fertility of lactating dairy cows is one of two important factors limiting successful reproductive management of dairy herds,” Pursley said. The other is detection of estrus, which can be managed with the synchronization of ovulation or estrus detection devices. Pregnancy rates from AI in lactating dairy cows has declined during the past 40 years. Low fertility is costing U.S. dairy producers about $250 million annually. “The foster mother of the human race is quicky becoming the goddess of low fertility,” Pursley said. In a related topic, Mike Peters, a master’s student working with Pursley presented an abstract entitled “Failure to achieve adequate pregnancy rates/AI after treatment with a modified version of Ovsynch®.” This research examined a simplified Ovsynch® protocol by giving the last GnRH injection on the same day as the PGF2α injection. It resulted in lower conception rate when compared with the recommended Ovsynch® protocol. Nutrition was the focus of another symposium in which Professor Mike Allen presented an invited talk on “Effects of diet on dry matter intake of lactating cows.” He addressed how various dietary factors such as fiber content and physical form including particle size, byproduct feeds, fiber digestibility, starch digestibility, fat content and type, and protein influence dry matter intake. Allen said these dietary factors may influence dairy nutritionists’ decisions in ration formulation because the dietary factors can affect feed intake. “Increasing dry matter intake may help increase the efficiency of milk production and milk yield,” he said. How milk yield and efficiency of cows fed monensin, a feed additive, along with effects on feed intake, body weight and condition changes were topics of two other abstracts, coauthored by Allen. Currently, the potential for use of monesin for lactating cows is in review by the U.S. Food and Drug Administration. It currently is not approved for use, Allen noted. Related abstracts presented by Allen’s graduate students and research assistants included the following: • “The effects of bm3 (brown midrib) corn silage on ruminal digestion and microbial efficiency,” given by
18 MICHIGAN DAIRY REVIEW Masahito Oba, doctoral student. The bm3 corn silage with lower lignin content, increased feed intake compared with conventional corn silage. Furthermore, dietary fiber disappeared more quickly from the rumen, thereby increasing microbial protein yield and efficiency. • “Comparison of methods to maintain rumen pH and milk fat content of cows consuming diets containing bm3 corn silage,” was given by Jackson S. Oliveira, a visiting professor from Brazil and a former MSU graduate student. The research showed that chop length of bm3 corn silage did not affect milk fat content, chewing time per day, feed intake or milk yield. • “Comparison of methods to evaluate in vitro neutral detergent fiber (NDF) digestibility of corn silage,” was presented by Oliveira and co-authored by David Main, research assistant, and Irelly Velez, a visiting undergraduate student from the University of Puerto Rico. This research found that in vitro neutral detergent fiber digestibility was different when determined by the standard “Van Soest” laboratory method compared with the Daisy II Fermentor (Ankom®, Inc.). Some fiber particles apparently escaped through the pores of the filter bags in the ANKOM system resulting in unrealistically high apparent fiber digestibility. • “Effects of brown midrib 3 mutation and brown midrib 3 plus Topcross™ high-oil corn silage on feed intake and milk yield of Holstein cows,” was presented by Jackie Ying, a research assistant working with Allen. Fat-corrected milk yield was over 4 pounds greater with high-oil bm3 corn silage than a normal corn hybrid. Feed intake was not affected. Other abstracts relating to nutrition and transition cows included: • “Effects of partial substitution of corn silage with corn grain in diets of transition dairy cows,” was presented by Douglas Mashek, a master’s student working with Beede. Mashek reported that cows in third or greater gestation fed a close-up diet with supplemental ground corn grain (21% of dietary dry matter) replacing corn silage had higher milk yield in early lactation. Similar responses to added corn grain were not found for pregnant heifers or cows in second gestation. The study was conducted in a commercial Michigan dairy. • “Effects of altering length of the late dry period of dairy cows,” also was given by Mashek and Beede. Increasing the length of the close-up period from 3 to about 6 weeks improved energy status of cows postpartum in two commercial farms. In one farm milk yield was greater with the longer dry period; however, the same result was not observed in the other farm. • “High versus low dietary calcium with negative cationanion difference prepartum: Effects on peripartum acid-base and calcium status,” was presented by Luis Rodriguez. Rodriguez, a former doctoral student of Beede’s, reported that feeding 1.98% calcium compared with 0.48% calcium in close-up diets supplemented with hydrochloric acid-treated heat-treated-extruded soybean meal resulted in more hypocalcemia and apparently reduced mobilization of
AUGUST 1999 calcium from bone around the time of calving. • “Varying dietary calcium concentration with negative cation-anion difference for late pregnant cows: Effects on peripartum acid-base and calcium status, feed intake, health and lactational performance,” was presented by Beede and cowritten with Tom Pilbeam and Sue Puffenbarger, research assistants. Close-up diets with hydrochloric acid-treated heattreated-extruded soybean meal resulted in lower urine pH (~6.5) compared with supplementation of soybean meal that was not acid treated (~8.1 urine pH). Blood calcium 12 to 24 hours after calving was greater for cows fed acid-treated soybean meal compared with that of cows not fed acid-treated soybean meal. Increasing dietary calcium (0.47, 0.99, 1.51 and 1.94%, dry basis) in close-up diets of cows fed acid-treated soybean meal did not influence health or postpartum milk yield. Besides having an adequate diet, physical exercise (walking 3.8 or 1.9 vs. 0 miles every other day for 60 days) improved overall fitness as measured by changes in heart rate of dairy cows challenged with a stress test, according to findings presented by Jill Davidson, a PhD student working with Beede. Their abstract was entitled, “Effects of programmed exercise on physical fitness of non-lactating, non-pregnant dairy cows.” Their report described the first study of a series in which an exercise model was developed and validated. In another area of physiology, Brian Whitlock, a master’s candidate working with Associate Professor Mike VandeHaar, presented the paper, “Influence of dietary protein on prepubertal mammary gland development in rapidly-grown heifers. VandeHaar and Tucker were contributing authors. Mammary development was similar for heifers fed high energy diets with 14, 16, or 19% crude protein from 3.5 months of age until 2 months after puberty. Kristin Perkins, another master’s candidate working with VandeHaar and Assistant Professor Jeanne Burton, gave her findings of the “Effect of negative energy balance on expression of L-selectin (CD62L) and Mac-1 (CD11b/CD18) by bovine blood neutrophils.” Their data suggested that experimentally induced negative energy balance was not responsible for immunosuppression in Holstein steers. Another highlight of MSU’s significant presence at the ADSA annual meeting was Jennifer Wells’ award for the most outstanding presentation in the Production Division Graduate Student Paper Competition. A master’s candidate, Wells’ work entitled “Taql PCR-RFLP in the glucocorticoid receptor gene of cattle,” was performed under the direction of Burton and Patty Sue Weber, a research associate, with assistance of Tracy Davis, an undergraduate intern. Their work found interesting mutations in a gene that may be involved in the ability of a cow’s immune system to fight infections. “We are particularly interested in determining associations of these mutations with mastitis susceptibility, using milk somatic cell count as the immune indicator,” Burton said.
MICHIGAN DAIRY REVIEW 19
Introducing the 1999 Graf Scholars Miriam Weber Dept. of Animal Science
o borrow a quote from Herbert Spencer, “The great aim of education is not knowledge but action.” Thanks to the visionary generosity of Dr. G.C. Graf, an alumnus of Michigan State College (B.S., Agriculture, 1934), four undergraduates enjoyed an opportunity this spring to put their knowledge into action in several laboratories in the Department of Animal Science. The department awarded $1000 Graf Scholarships to Alexis Bergstrom, Karissa Slusher, Karen Smith, and Amy Steffey for undergraduate research in dairy science. Alexis Bergstrom is working with Dr. Jeanne Burton on a research project to evaluate the efficacy of a new assay for M. paratuberculosis, the bacteria that causes Johne’s disease, in individual and bulk milk samples. Origen, Inc. in Lansing developed this molecular diagnostic assay as an alternative to tests currently available that are relatively timeconsuming. Alexis, a senior in Animal Science from Grand Haven, Michigan, has been assisting with various departmental research projects since 1996. Karissa Slusher is evaluating indicators of pain associated with lameness in dairy cows under the guidance of Dr. Adroaldo Zanella. Lameness causes a significant financial loss annually in the
Michigan dairy industry. Using a lameness scoring system developed by Drs. D.J. Sprecher and J.B. Kaneene, Karissa’s project will determine how varying degrees of lameness affect a cow’s pain response. A senior in Animal Science, Karissa participated in 4H and recently gained considerable experience with dairy cattle through work on research projects in Dr. Dave Beede’s laboratory. Karen Smith is building on her dairy interests and experience in Dr. Jeanne Burton’s laboratory on a project to passively immunize the bovine mammary gland against mastitis. Karen’s work focuses on producing antibodies in the blood of steers that have been immunized with the J5 mastitis vaccine. Karen grew up on a dairy farm near Onondaga and has been active in 4-H and the Michigan Brown Swiss Cattle Breeders Association. A senior in Animal Science, Karen plans to work after graduation as a research technician with Dr. Burton. Amy Steffey is working with Dr. George Smith to improve the reproductive efficiency of dairy herds. Amy’s project focuses on understanding the mechanisms that regulate ovulation in dairy cattle. An increased understanding of this area will increase our ability to manipulate the estrous cycle of dairy cows. This spring, Amy Steffey graduated with the highest grade point aver-
age in the College of Agriculture and Natural Resources. She is from a dairy farm near Stockbridge and will enter veterinary school at MSU in the fall. Spartan Dairy Associates These projects marked an initial step in establishing the Spartan Dairy Associates program in the Department of Animal Science at Michigan State University. Through the philanthropic spirit of Dr. G.C. and Gwendolyn Graf, Spartan Dairy Associates was created to encourage students to promote the dairy industry by becoming active partners in its growth. Students can participate in dairy farm analysis and decision-making opportunities; undergraduate research in laboratory, dairy farm, and agribusiness settings; and short-term studies at other universities in the U.S. and abroad. Participation in these undergraduate research experiences will allow tomorrow’s leaders to develop an integrated perspective of dairy science. Additional opportunities in the Dairy Associates Program are provided through support from the Roger and Marjorie Mellenberger Dairy Associates Program Enhancement Fund, the Frederick Pierce Halbert Dairy Memorial Endowed Scholarship Fund, the MSU College of Agriculture and Natural Resources, the Michigan Agricultural Experiment Station, and the Department of Animal Science.
Corn Harvest 1999, Consider Your Options Dave Beede and Mike Allen Dept. of Animal Science
ue to extra heat units and ample, timely moisture, the 1999 corn harvest for much of Michigan is expected to be extremely good, if not tremendous. The corn harvest forecast for most of the Midwest is similar. Dr. Wayne Purcell of Virginia Tech University, in his July 13 report
forecasts a bearish price scenario for grains and oilseeds for the foreseeable future (4). Planted corn acreage nationally was up 12.6% in 1998 and 8.9% in 1999 compared with 1995. New-crop price offers for corn grain in parts of the Midwest are as low as $1.30 to $1.50 per bushel. Scenarios are similar for soybeans with planted acreage up 18.5% this year over 1995, and new-crop offers are moving toward
$3.50 per bushel, with November futures barely above $4.00. Whereas this is especially dismal for crop farmers, it necessitates consideration of options for dairy producers to add value to their homegrown corn harvest. Some considerations of how to handle this bumper crop are in order. Consider these points: • Don’t use the calendar to decide when to cut for corn silage — you may
20 MICHIGAN DAIRY REVIEW get caught! With our tremendous growing season, corn plants will be ready for the silo earlier than usual. Monitor moisture content of corn plants. For highest feeding value, moisture content in horizontal (bunker) silos should average 65 to 70%; for vertical (upright) silos 60 to 65% moisture is the target (1, 2). Lower leaves may still be mostly green (not fired or brown) and the moisture content on target! • Obviously, selling corn grain on the open market isn’t going to fetch much income, and in all likelihood will not be profitable. • Putting some of the extra corn through dairy cows as corn silage, high moisture corn, or dry processed corn may increase its value if the price of milk stays high enough. However, carefully watch for signs of ruminal acidosis in your cows and correct the ration immediately if problems arise. Some extra hay or ample haylage may be needed to avoid or correct this potential problem. • Many dairy producers still have considerable 1998 corn silage in storage. How are your actual or estimated corn silage and corn grain inventories relative to projected needs for the next 12 to 16 months? • Even if you’ve fed most of last year’s harvest and will fill available storage space again, perhaps you should consider storing additional corn silage and (or) corn grain. • This year’s projected bumper corn crop provides opportunity to build inventory reserves, which can be very advantageous. • Increasing corn silage inventory on the farm can help avoid the “new corn silage slump” characterized by lower than expected milk yield because the new corn silage has not “steeped” long enough and has lower feeding value than it will have later in the Fall or early Winter (1). If enough inventory of silage from the previous year is available, one would not get into the position of having to feed this new, “un-steeped” corn silage. Also, extra
inventory will provide a buffer so that farms do not run out of corn silage before the next harvest. Carrying an extra inventory of 3 or 4 months of corn silage this year and in subsequent years likely is a profitable strategy; especially with low corn prices and a reasonably strong milk price. • If you haven’t already constructed extra bunker space to accommodate extra silage, using plastic silage bags might work well in this harvest season. • Gain additional capacity in your current horizontal silos by increasing packing. Silo dry matter capacities were increased up to 60% as packing intensity increased either by more time spent packing or by use of heavier equipment (5). • Just making a pile of corn silage, even if you think you’ve packed it well, will result in considerable dry matter losses, especially if it’s not covered with plastic (up to 30% dry matter losses in the top 2 to 4 feet) (6), greatly reducing the profit potential of the extra corn silage inventory. • Beware. Chopping finer to increase packing density may seem like a good idea. But, this may decrease ruminal buffering leading to ruminal acidosis, especially if you’re feeding more corn grain than usual this coming year. Theoretical length of cut for unprocessed (unrolled) corn silage is 3/8 inch, whereas 3/4 inch is recommended for processed corn silage. • Of course, making this extra corn into silage might not be as advantageous if the hybrid grown is designed for corn grain production, rather than a hybrid specifically developed for corn silage which has higher fiber digestibility (2). • Be sure to do comparisons of the value (price or cost) of corn silage, high moisture corn, or dry corn on an equal dry matter basis. Refer to the article by Durst (3) if you need a refresher on how to do this. • The best options will vary among farms. Calculating the real cost
AUGUST 1999 to produce each ton or acre of corn silage (or grain) and accurately estimating yield are paramount in order to make informed decisions of how to best utilize the extra corn (or soybeans) with the expected grain and oilseed prices and forecasted price of milk. Also, consider the real costs of storage on-farm or in country elevators in your analysis. • Also, do you have the opportunity to feed-out some animals for beef or add some milking cows? These may or may not be short-term profit possibilities, but they need evaluation. According to Purcell (4), if weather conditions and planted acreages are comparable to this year, low grain prices will be the norm for at least the next couple of years. Similar management options and decisions will present themselves again. Thinking longer range about building more feed storage should be considered carefully. And, although too late for this harvest season, use of hedge positions in the commodities futures market may offer potential in the future as well (4). References 1. Allen, M. November, 1997. The Slump.Michigan Dairy Review 2(4):12. 2. Allen, M. November, 1998. Corn silage processing: It’s a matter of faith. Michigan Dairy Review 3(4): 8-11. 3. Durst, P. May, 1999. How to evaluate prices for alternative feed sources. Michigan Dairy Review. 4(2):4-5. 4. Purcell, W. July 13, 1999. Weekly Purcell Agricultural Commodity Market Report. Ag. and Applied Economics Dept., Virginia Tech, Blacksburg. 5. Ruppel, K. et al. 1995. J. Dairy Sci. 78:141. 6. Thomas, C. May, 1998. Cover your bunker silo: 8-to-1 payback. Michigan Dairy Review 3(2): 18-19.
Calendar of Events October 7, 1999 Dairy Feeder School Hudson, MI Contact: Roberta Weber at 517-439-9301.
MICHIGAN DAIRY REVIEW 21 Make Plans to Attend the
Tri-State Dairy Management Conference November 10 & 11, 1999 Grand Wayne Center 120 West Jefferson Boulvevard Fort Wayne, Indiana Objectives of Conference The purpose of the Tri-State Dairy Management Conference is to facilitate the delivery of state-of-the-art technology and information pertaining to the management of competitive dairy herds in Indiana, Michigan, and Ohio.
Management Conference when making reservations. Reservations can be made directly by calling 1-800HILTONS or (219) 420-1100. Other hotels in the area include:
Intended Audience Dairy producers in Indiana, Michigan, and Ohio and dairy industry personnel
Court Yard Marriott 1619 W. Washington Center Rd. 1-800-321-2211
Location Grand Wayne Center 120 West Jefferson Boulevard Fort Wayne, Indiana 46802 Telephone: (219) 426-4100 FAX: (219) 420-9080
Holiday Inn-Downtown 300 E. Washington Boulevard 1-800-HOLIDAY
Registration Fee $99 per person; including refreshments during breaks, one breakfast, two lunches, and a copy of the proceedings. Deadline: October 15, 1999. Accommodations Please make room reservations directly with area hotels. Participants are encouraged to check-in prior to the Conference. The preferred hotel is: Fort Wayne Hilton 1020 South Calhoun Street P.O. Box 12049 Fort Wayne, Indiana 46862-2049 (219) 420-1100 The Fort Wayne Hilton is connected to the Grand Wayne Center and has a block of rooms reserved for the Tri-State Dairy Management Conference. Rooms are $82.00 plus tax for single, double, triple, or quad occupancy. Room reservations need to be made by October 12, 1999 to receive the discounted room rate. Reservations received after that date will be confirmed based on space availability at the regular hotel rate. Mention that you are with the Tri-State Dairy
Signature Inn 1734 W. Washington Center Rd. 1-800-822-5252 Days Inn North Hotel 5250 Distribution Dr. 1-800-329-7466 Information For more information about the Conference, contact: Ms. Jennifer Winkler at (614) 688-3143 or via email ([email protected]
) or Dr. Normand St-Pierre at (614) 2926507, The Ohio State University; Dr. David Beede at (517) 432-5400, Michigan State University; Dr. Michael Schutz at (765) 494-9478, Purdue University. Visit the Tri-State Dairy Conferences web site at: www2.ag.ohio-state.edu/~ansci/tristate/tristate.htm Sponsored by:
22 MICHIGAN DAIRY REVIEW
Agenda Wednesday, November 10
Thursday, November 11
8:00 - 9:00
6:30 - 7:30
9:00 - 9:10
Registration (refreshments provided) Welcome
The Tri-State Advantage Moderator: Dr. David Beede 9:10 - 10:30
10:30 - 11:00 11:00 - 11:45 11:45 - 12:00 backs 12:00 - 1:00
Producer Panel: Why I Chose to Locate in the Tri-State Area Mr. Richard Johnson Mr. John Vander Hoff Dr. Leon Weaver Break (Refreshments provided) The Tri-State Market Advantage Dr. Robert Jacobson Summary of Key Points and Draw Dr. Normand St-Pierre Lunch (Provided)
Animal Health and Well-being Moderator: Dr. Simon Kenyon 7:30 - 9:30
9:30 - 10:00
10:00 - 12:00
3:00 - 3:30
Breakout 1: Feet and Legs Dr. Jan Shearer Breakout 2: Cow Behavior Dr. Richard Grant Breakout 3: Heat Detection and Conception Dr. Jeff Stevenson Break (Refreshments provided)
Breakout 7: Biosecurity - Purchasing Animals Dr. Roger Mellenberger Breakout 8: Managing Health Problems of Transition Cows Dr. Bimbo Welker Breakout 9: Troubleshooting Somatic Cell Count Problems Dr. Simon Kenyon Break (Refreshments provided)
Business Management Moderator: Dr. Normand St-Pierre
Management Eye on the Cows Moderator: Dr. Herbert Bucholtz 1:00 - 3:00*
Buffet Breakfast (provided)
12:00 - 1:00
Breakout 10: Margin Protection or Gambler’s Ruin - What is Your Marketing Plan? Dr. Cameron Thraen Breakout 11: Basis for Facility Decisions: Designing Facilities for Your Management Style Dr. William Bickert Breakout 12: Business Structures: Legal and Financial Implications Mr. Paul Wright, L. P. A. Lunch (provided)
Labor Management Moderator: Dr. Maurice Eastridge
Dairying and the Environment Moderator: Dr. Michael Schutz
3:30 - 5:30
1:00 - 1:30
5:30 - 7:00
Breakout 4: Producer Panel: How We Manage Employees Mr. John Douglass Mr. Merrill Kelsay Mr. Ken Nobis Breakout 5: How Do You Hire and Train Employees Dr. Dennis Cooper Breakout 6: Family Labor Issues Dr. Bernard Erven Reception (Hors d’oeuvres provided)
1:30 - 2:00 2:00 - 2:45
2:45 - 3:30
3:30 - 3:45
Right to Farm Legislation: Impact in the Tri-State Area Mr. Wayne Whitman Dealing with Neighbors Mr. Willard DeGolyer Producer Panel: Public Relations Efforts in Our Farms Mr. Dale Arbaugh Mr. Jim Hardy Mr. John Hardy Business Structure and the New Environment Dr. Mike Boehlje Closing Remarks Dr. David Beede
*All breakouts are 50 minutes with 10 minutes between breakouts. Each participant may attend two of the three breakouts in each session.
MICHIGAN DAIRY REVIEW 23
Registration Form Name: Farm/Company Name: Address: City: Number Attending: Amount Enclosed $ $ $ $
Zip: Email: Registration($99/person)* Extra Proceedings ($15/copy) Shipping ($2.75/copy; only if Proceedings are to be mailed) Total
Telephone: Names of additional attendees:
*Pre-registration is required. Please include an additional charge of $20 per registration for registrations mailed after the registration deadline. No refunds are permitted. Registration deadline: October 15, 1999. Make checks payable to: “The Ohio State University.” We are unable to accept credit cards at this time. Mail registration form & registration fee to: Ms. Jennifer Winkler, 214 Animal Science Building, 2029 Fyffe Road, Columbus, Ohio 43210.
Program Participants Mr. Dale Arbaugh, Arbavue Farms, Jewett, OH
Mr. Merrill Kelsay, Kelsay Farms, Whiteland, IN
Dr. David Beede, Professor, Department of Animal Science, Michigan State University
Dr. Simon Kenyon, Associate Professor, Department of Veterinary Clinical Sciences, Purdue University
Dr. William Bickert, Professor, Department of Agricultural Engineering, Michigan State University
Dr. Roger Mellenberger, Professor, Department of Animal Science, Michigan State University
Dr. Mike Boehlje, Professor, Department of Agricultural Economics, Purdue University
Mr. Ken Nobis, Nobis Dairy Farms, St. Johns, MI
Dr. Herbert Bucholtz, Professor, Department of Animal Science, Michigan State University Dr. Dennis Cooper, Professor, Animal and Food Science Department, University of Wisconsin - River Falls Mr. Willard DeGolyer, Table Rock Farm, Castile, NY Mr. John Douglass, Catalpadale Farm, Marshallville, OH Dr. Maurice Eastridge, Professor, Department of Animal Sciences, The Ohio State University Dr. Bernard Erven, Professor, Department of Agricultural, Environmental, and Developmental Economics, The Ohio State University Dr. Richard Grant, Associate Professor, Department of Animal Science, University of Nebraska Mr. Jim Hardy and Mr. John Hardy, Maple Row Dairy, Saranac, MI Dr. Robert Jacobson, Professor Emeritus, Department of Agricultural, Environmental, and Developmental Economics, The Ohio State University
Dr. Michael Schutz, Assistant Professor, Department of Animal Sciences, Purdue University Dr. Jan Shearer, Associate Professor, Department of Large Animal Clinical Sciences, University of Florida Dr. Normand St-Pierre, Associate Professor, Department of Animal Sciences, The Ohio State University Dr. Jeff Stevenson, Professor, Department of Animal Sciences/ Industry, Kansas State University Dr. Cameron Thraen, Associate Professor, Department of Agricultural, Environmental, and Developmental Economics, The Ohio State University Mr. John Vander Hoff, Vander Hoff Farms, Coldwater, MI Dr. Leon Weaver, Bridgewater Dairy, LLC., Montpelier, OH Dr. Bimbo Welker, Associate Professor, College of Veterinary Medicine - Marysville Ambulatory Practice, The Ohio State University, Marysville, OH Mr. Wayne Whitman, Manager, Right to Farm Program, Environmental Stewardship Division, Michigan Department of Agriculture
Mr. Richard Johnson, Sunset Dairy, Rolling Prairie, IN Mr. Paul Wright, Wright & Logan Co., L.P.A., Dublin, OH
24 MICHIGAN DAIRY REVIEW MICHIGAN STATE UNIVERSITY
Michigan Dairy Review Progressing Toward the 21st Century Number 3
The Michigan Dairy Review is published in February, May, August, and November by the Dairy Programs Group at Michigan State University. Its objective is to provide useful information to the dairy producers and dairy-allied industries of Michigan to enhance the potential success of their businesses. The Michigan Dairy Review can be located on the World Wide Web at http:/ /www.canr.msu.edu/dept/ans/dairyext.html or http://www.canr.msu.edu/dept/ans/Home/Dairy/Extension/extension.html. Editor .............................................................................................................................................................. Dr. H. Allen Tucker Final Copy Editor .................................................................................................................................................... Dr. Kathy Lee Publisher ...................................................................................................................................................................... Pam Jahnke WWW Site Manager ............................................................................................................................... Dr. Russell W. Erickson Managing Publisher ........................................................................................................................................ Dr. David K. Beede Circulation ............................................................................................................................................................................. 6,900 Permission to reprint or translate and reprint from Michigan Dairy Review is granted provided that the intended meaning is not changed and that explicit credit is given to the authors and publication source. If the original article is adapted, paraphrased, or changed in any other way please send facsimile (517-432-0147) of the new version to the Managing Publisher for verification of meaning and approval. As a courtesy, please send a copy of the reprinted article to the Managing Publisher (Dr. David Beede, Michigan State University, Department of Animal Science, 2265K Anthony Hall, East Lansing, MI 48824-1225). Product and service names are used only for the sake of clarity and in no way imply endorsement over similar products or services which may be just as effective. MSU is an Affirmative-Action Equal-Opportunity Institution. MSU programs are open to all without regard to race, color, national origin, sex, disability, age, or religion.
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