Student Competition: Metabolism and Nutrition, Nutrition I

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Dervan D. S. L. Bryan*, Dawn A. Abbott, and Henry L . Classen, ..... nested within market class. Pearson correlation was used to determine correlations.

Student Competition: Metabolism and Nutrition, Nutrition I 46   An in vitro technique for measuring the digestion kinetics of dietary proteins fed to poultry. Dervan D. S. L. Bryan*, Dawn A. Abbott, and Henry L. Classen, University of Saskatchewan, Saskatoon, SK, Canada. Obtaining digestion kinetics data for CP ingredients before diet formulation is difficult. An in vitro technique is proposed for measuring the digestion kinetics of protein sources fed to poultry using a 30-min gastric and 4-h intestinal phase to mimic digestion in chickens. Protein sources (500 mg of CP = % N × 6.25) were digested with 0.05 mg of guar gum, 8.5 mL of 0.1 N HCl, and 1.5 mL of pepsin in 50-mL polyethylene centrifuge tubes for 30 min in a shaking water bath (150 strokes/min; 30-mm stroke length) at 41°C. After the gastric phase, all tube pH were adjusted to 7 ± 0.5 with 500 µL of 4.9 N NaOH, 9.5 mL of sodium acetate buffer (pH 12.5), followed by the addition of 6.5 mL of pancreatin. Three glass marbles were placed in each tube and all tubes were incubated in the water bath for 4 h. At 0, 15, 30, 45, 60, 90, 120, 150, 180, and 240 min during the intestinal phase, 0.5-mL aliquots were collected. Digestion (DIG) was measured calorimetrically via a ninhydrin assay where aliquots were diluted (1:820) with 10 mL of 0.1 N HCl followed by 10 mL of sodium acetate buffer pH 6.5 and H2O. Samples were mixed with ninhydrin reagent (2:1) at 100°C ± 2 for 15 min and absorbance read at 568 nm on a spectrophotometer after 10 min of cooling. Each meal CP DIG was calculated over time as meal aliquots absorbance expressed as a percentage of total absorbance of meal after 24-h digestion in 6 N HCl at 110°C. To validate the assay, 5 replications per run of soybean (SBM), corn gluten (CGM), and corn distillers dried grains with solubles (CDDGS) meals were digested in 2 runs. Data were modeled with PROC NLIN procedure and inter and intra coefficient of variation (CV) assessed with PROC MEANS of SAS 9.4. The DIG values at 150 min were SBM 87 ± 4%, CGM 63 ± 10%, and CDDGS 60 ± 4%. Intra-assay CV for SBM, CGM and CDDGS were 3 to 4, 3 to 4, and 2 to 4%, respectively, whereas the inter-assay CV values were 5, 15, and 4%, respectively. The respective estimated digestion rates for SBM, CGM and CDDGS were 0.58, 0.42, and 0.40 (%/min). In conclusion, the proposed in vitro technique determined the rate and extent of digestion for the meals while achieving low intra- and inter-assay variability. Key Words: in vitro, digestion kinetics, soybean meal, corn gluten meal, corn distillers grains 47   Effects of modifying diet and feed manufacture concern areas that are notorious for decreasing pellet quality. Tyler R. Rigby*, Brian G. Glover, Kolby L. Foltz, and Joseph S. Moritz, West Virginia University, Morgantown, WV. The production of high quality pellets has often been described as more art than science due to the multitude of variables that affect pellet quality. Variables may interact with one another to exacerbate negative effects on the pelleting process. The objectives of the current study were to examine the feed manufacture and pellet quality effects of 4 different feed milling concern areas utilizing semi-wet corn (>15% moisture) in all formulations. Each area of concern was evaluated using either a condition of high concern or a corresponding condition of low concern. Treatments included high or low mixer added fat (2.5 vs. 0.5%), high or low distillers dried grains with solubles (DDGS; 8 vs. 2%), high or low dicalcium phosphate (1.63 vs. 0.31%), and high or low steam conditioning temperature (82 vs. 74°C). All diets were formulated to 16

similar broiler starter requirements based on commercial nutrient values. A randomized complete block design using a 4 × 2 factorial arrangement was implemented with 3 replications per treatment and 136-kg allotments of feed as the experimental unit. Contrasts were performed to better understand main effect interactions. Semi-wet corn was analyzed to contain 16.6% moisture. Area of concern and level of concern interacted to effect pellet durability, percent pellets, and particle size (P < 0.05). High mixer added fat and low dicalcium phosphate decreased pellet durability, percent pellets, and feed particle size (P < 0.05). Conditions of high concern for DDGS and steam conditioning did not produce similar negative effects (P > 0.05). Pellet production rate, conditioner electrical energy usage, and pellet mill electrical energy usage were not affected by treatments (P > 0.05), likely due to semi-wet corn inhibiting opportunities for treatments to improve lubrication at the mash die interface. A greater appreciation of variable interactive effects benefits pellet mill operators, nutritionists, and pelleting aid vendors to better circumvent hurdles encountered during the pelleting process. Key Words: pellets, fat, DDGS, dicalcium phosphate, steam conditioning 48   Maternally derived anti-fibroblast growth factor 23 antibody as new tool to reduce phosphorus requirement of chicks. Zhouzheng Ren*, Daniel E. Bütz, Jordan M. Sand, and Mark E. Cook, Department of Animal Sciences, University of WisconsinMadison, Madison, WI. Novel means to reduce phosphate input into poultry feeds and increase its retention would preserve natural reserves and reduce the environmental effect of poultry production. Here, we show that a maternally derived antibody to a fibroblast growth factor-23 (FGF-23) peptide (GMNPPPYS) alleviated phosphorus deficiency in chicks fed low non-phytate phosphorus (nPP, 0.13 and 0.20%) diets. White Leghorn laying hens were vaccinated with either an adjuvant control or the synthetic FGF-23 peptide, and chicks with control or anti-FGF-23 maternal antibodies were fed a diet containing either 0.13 or 0.45% nPP (experiment 1), and 0.20 or 0.45% nPP (experiment 2) for14 d. In both experiments, independent of maternal FGF-23 antibody, decreasing nPP from 0.45 to 0.13 or 0.2% decreased (P < 0.05) body weight (>15%), feed efficiency (>20%), tibia ash (>12%), excreta phosphorus (>22%), plasma phosphorus (>28%) and plasma FGF-23 (>17%). In experiment 1, chicks with maternal anti-FGF-23 antibody had increased bone ash (10.5%), and decreased excreta phosphate (7.4%) compared with chicks with control antibody (main effects, P < 0.05). In addition, mortality, posture scores and bone lesion scores were decreased and plasma phosphate increased (2 fold) in anti-FGF-23 chicks fed 0.13% nPP, compared with those with control antibody on the same diet (P < 0.05). In experiment 2, chicks with maternal anti-FGF-23 antibody had decreased excreta phosphate (4.4%, P = 0.064) and increased plasma phosphate (13.7%) and plasma 1,25 (OH)2D3 (20.4%) compared with chicks with control antibody (main effects, P < 0.05). In addition, body weight (24.7%) and feed efficiency (46.2%) was increased in chicks with maternal anti-FGF-23 fed 0.20% nPP, compared with those with control antibody on the same diet (P < 0.001). In conclusion, maternally derived anti-FGF-23 antibody reduced signs of phosphorus deficiency in chicks fed diets containing either 0.13 or 0.20% nPP, probably by way of increased phosphorus retention. Key Words: FGF-23, antibody, phosphorus, requirement, chick Poult. Sci. 95(E-Suppl. 1)

49   Split feeding as an alternative system to improve shell quality of aged hens. Anikó Molnár*1,2, Luc Maertens1, Johan Buyse3, Johan Zoons2, and Evelyne Delezie1, 1Institute for Agricultural and Fisheries Research, Melle, Belgium, 2Experimental Poultry Center, Geel, Belgium, 3KU Leuven, Leuven, Belgium. In this experiment, we investigated the effect of 5 split feeding treatments on performance and egg quality of individually housed layers (75–90 wk, Dekalb White, n = 12/treatment). The control treatment (T1) received the same feed in the morning (M) and in the afternoon (A), which contained fine (F) and coarse limestone (CLS) at ratio 50:50. For the split treatments, the ratio of FLS and CLS was 50:50 or 30:70 and time of administration (M/A) differed. The following treatments were given: T2 = 50CM:50FA, T3 = 30FA:70CA, T4 = 50FM:50CA, T5 = 30FM:20FA+50CA, and T6 = 30FM:70CA. Data were analyzed with a linear mixed effects model in R 3.1. Due to an unexpectedly low feed intake and laying percentage, T1 could not be compared with the split treatments and was excluded from the analysis. Results indicated that time of feeding FLS and CLS affect production and shell quality. When only FLS was fed in the afternoon (T2) shell formation had to be supported by bone reserves during the night which resulted in low shell thickness (ST). Although ST decreased in all treatments from 403.2 to 390.2 µm between 76 and 90 wk of age (P = 0.016), highest ST was obtained in T4 (408.0 µm) and T5 (401.7 µm), whereas ST of T2 (388.2 µm) and T3 (394.3 µm) was the lowest (P = 0.058). When all LS was fed in the afternoon (T3), egg weight (EW) increased and ST decreased. At 88 wk of age, eggs weighed 60.4 g in T2, whereas EW was 66.3 g in T3 and 67.3 g in T6 at 88 wk (P ≤ 0.05). Providing FLS in the morning and CLS in the afternoon in ratios of 50:50 (T4), 30:20+50 (T5), or 30:70 (T6), however, resulted not only in favorable shell quality but also performance: laying percentage of hens in T4 (89.6%) and T5 (92.9%) was higher than in T2 (66.1%) at 89 to 90 wk of age (P ≤ 0.05). Laying percentage of T3 (71.7%) was lower than that of T5, and T6 (86.8%) did not differ from the other treatments. Feed conversion ratio (FCR) in T2 was higher than in T5, T3, and T6 at 87–88 wk (P ≤ 0.05). At 89–90 wk, FCR of T3 increased, and T2 and T3 had a higher FCR compared with T4, T5 and T6. Therefore, T4, T5, and T6 can be considered for further research to study whether this feeding system could also be applied under field conditions. Key Words: split feeding, egg quality, limestone, aged layer, performance 50   Evaluation of the lysine requirement of 7- to 28-day-old Bobwhite quail. Ariel N. Bergeron*, Jose W. Charal, and Theresia A. Lavergne, LSU Agricultural Center, Baton Rouge, LA. Two trials were conducted to evaluate the lysine requirement of 7- to 28-d-old Bobwhite quail. A total of 360 Bobwhite quail were used. In each trial, 180 quail were allotted and placed on 1 of 5 treatment diets with 6 replications of 6 quail per replicate on d 7 of age. The treatment diets were formulated to contain 1.33, 1.53, 1.73, 1.93, or 2.13% total lysine. All diets contained the same amounts of corn and soybean meal, and various amounts of Biolys (54.6% l-lysine) were substituted for isonitrogenous amounts of l-glutamic acid. Diets were formulated to contain 2,900 kcal/kg ME and 4.36% N. Feed and water were provided ad libitum. Each trial was conducted for 21 d. Quail were weighed at initiation of the experiment (d 7 of age), at d 14 of age, at d 21 of age, and at the termination of the experiment (d 28 of age) to determine body weight (BW), average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (GF). In both trials, there were no differences (P > 0.05) in BW, ADG, ADFI, or GF for quail fed any of the lysine levels. In the first trial, average BW, ADG, ADFI, and GF Poult. Sci. 95(E-Suppl. 1)

were 73.97 g, 2.73 g, 6.04 g, and 0.45, respectively. Average BW, ADG, ADFI, and GF were 59.28 g, 1.82 g, 5.92 g, and 0.32, respectively, in the second trial. The results of these trials indicate that the NRC (1994) recommended lysine requirement of 1.73% is adequate for 7- to 28-dold quail. Additional research is needed to determine the exact lysine requirement of 7- to 28-d-old Bobwhite quail. Key Words: Bobwhite quail, lysine, average daily gain, average daily feed intake, feed efficiency 51   Effects of feed form, environment, and caloric density on energy partitioning and subsequent broiler performance. Brian G. Glover*, Kolby L. Foltz, Kenneth J. Ryan, and Joseph S. Moritz, West Virginia University, Morgantown, WV. Benefits of improved pellet quality on broiler performance have been well documented. Feed prehensive energy savings acquired from an improved crumble/pellet percentage could affect dietary caloric requirements. The objective of the study was to assess the effect of variations of crumble/pellet percentages and dietary caloric density on broilers reared on clean shavings and built-up litter. All diets were batched, mixed, steam conditioned to approximately 80°C, extruded through a 4- × 38-mm pellet die, and crumbled at the West Virginia University pilot feed mill. Bird density and feeder space access was 0.06 m2/bird and 1.2 cm/bird, respectfully. A split-plot design was used. Whole plot treatments of clean shavings or built-up litter were randomly assigned to a room (11 × 7.32 m). The design at the subplot level within room was a randomized block design with 8 blocks and a 2 × 2 factorial treatment structure. The subplot treatment structure consisted of either a standard (30% crumble/pellet) or improved feed form (80% crumble/ pellet), and either standard or increased (+110 kcal/kg) caloric density. Study replication allowed testing for the presence of room effect at the whole plot level. The main effects of improved feed form and increased caloric density significantly decreased feed conversion ratio (P < 0.05). Broilers consuming an improved feed form increased feed intake, live weight gain, hot breast weight, and visceral fat pad weight (P < 0.05). A feed form by caloric density 2-way interaction was observed for visceral fat pad weight and yield responses (P < 0.05) demonstrating improved crumble/pellet percentage in combination with increased caloric density provided the most energy on average for storage in the form of adipose tissue. These data suggest that improvements in feed form may provide feed prehensive energy savings that could be partitioned to other biological processes. Key Words: feed form, pellet, broiler, caloric density, crumble 52   Diet induced thermogenesis in broilers: A precision feeding approach. Sasha A. S. van der Klein*, Chris A. Ouellette, and Martin J. Zuidhof, Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada. Understanding individual bird and diet effects on net energy available for productive processes is the next step in optimal feed formulation. The aim of this study was to gain insight into factors contributing to energy lost via heat. We estimated the effect of dietary metabolizable energy (ME) level and ME intake on ME requirements for maintenance (MEm) and residual feed intake (RFI). We hypothesized that diets containing low or high ME would have different rates of associated diet induced thermogenesis (DIT), and that reduced feed intake would reduce heat loss, and thus result in a lower RFI. At hatch, 48 Ross 308 broilers were randomly allocated in 1 of 4 pens, all of which were equipped with a precision feeding station. Isonitrogenous diets varying in ME content 17

were fed at different levels using a precision feeding station. Pens were randomly assigned to a high ME (3,150 kcal/kg) or a low ME (2,900 kcal/kg) diet. Birds were trained to use the station as a group from 0 to 10 d of age. At d 10, birds received a radio frequency identification tag and were transitioned to individual feeding. At d 19, 2 birds per pen were assigned to ad libitum treatment and used as master birds. The other birds were randomly coupled to one of the 2 master birds per pen, and received daily 90, 80, 70, 60, or 50% of its master feed intake. MEm and growth were estimated by a non-linear mixed model explaining ME intake (MEI) as a function of metabolic BW and gain. The RFI was the random error term of the model. MEm were significantly different between birds fed the low and high ME diets (127 and 140 kcal/kg0.57, respectively; P < 0.001). There was a linear relationship between MEm and MEI (P < 0.001). As feed intake increased, MEm was increased by 0.20 kcal0.57/kcal consumed. Hence, 20% of additional ME consumed was lost as heat. The high ME diet increased MEm by 8.41 kcal/kg0.57. There was also a linear relationship between RFI and MEI (P < 0.001). For every kcal increase in MEI, RFI increased by 0.09 kcal. The high ME diet increased RFI by 4.20 kcal. Thus, we conclude that lower dietary ME level and ME intake both reduced DIT and decreased RFI. Key Words: precision feeding, energy, maintenance, residual feed intake, requirements 53   The rate and extent of starch digestion affects digestive tract morphology and ileal brake activation in broiler chickens. Eugenia Herwig*, Rachel Savary, Karen Schwean-Lardner, and Henry L. Classen, University of Saskatchewan, Saskatoon, SK, Canada. Slowly digested starch (SDS) positively affects broiler performance, but little is known of the mechanisms involved. It was hypothesized activation of the ileal brake by the presence of starch in the distal small intestine increases digesta retention time and nutrient digestibility. Two semi-purified starch sources with differing in vitro digestibility (wheat, rapidly digested starch, RDS; pea, SDS) were used in 6 diets with differing RDS/SDS ratios: 100/0, 80/20, 60/40, 40/60, 20/80 and 0/100. The diets were fed to male Ross 308 broilers housed in litter floor pens from 0 to 28 d. At 14 and 28 d, digestive tract (full and empty weights, length) and digesta pH measurements were recorded. Serum samples were taken at 28 d to measure chicken Peptide YY (PYY), as an indicator of ileal brake activation. Data were analyzed with regression analysis using SAS 9.4, with P < 0.05 considered significant. At 14 d, relative empty weights of the proventriculus, ileum and ceca increased linearly with SDS level, whereas jejunum weight changed quadratically with a maximum at 80% SDS birds. Besides the ileum, the relative contents of the gizzard, duodenum, jejunum and ceca increased linearly with SDS inclusion, while crop and ileal contents increased quadratically. At 28 d, the relative weight of the digestive tract segments increased with SDS level, except for the gizzard and duodenum, along with the crop, jejunum and ileum contents. Only the relative ileum length increased with SDS at 14 d, while the relative length of the small intestine increased with SDS at 28 d. Cecal pH decreased linearly with SDS level at 14 d, but not 28 d. Crop pH at 28 d showed a quadratic response to SDS level, with the lowest pH for the 60% SDS diet. There were no significant differences in PYY concentration. In conclusion, changes in digestive tract size and content suggest ileal brake activation in broiler chickens fed SDS, but this was not confirmed by serum PYY level. Key Words: slowly digested starch, rapidly digested starch, digestive tract morphology, ileal brake, broilers

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54   Starch digestibility and apparent metabolizable energy of western Canadian wheat market classes in broiler chickens. Namalika D. Karunaratne*, Pierre Hucl, Ravindra N. Chibbar, Curtis J. Pozniak, Dawn A. Abbott, and Henry L. Classen, University of Saskatchewan, Saskatoon, SK, Canada. Wheat is the primary grain fed to poultry in western Canada, but its nutritional quality, including the nature of its starch digestibility, may be affected by wheat market class. The objectives of this study were to determine the rate and extent of starch digestibility of wheat market classes in broiler chickens, and to determine the relationship between starch digestibility and wheat AMEn. In vitro starch digestion was assessed using gastric and small intestinal phases mimicking the chicken digestive tract, while in vivo evaluation used 468 d-old male broiler chickens randomly assigned to dietary treatments (6 cages/ treatment, 6 birds/cage) from 0 to 21 d of age. The study evaluated 2 wheat cultivars from each of 6 western Canadian wheat classes: Canadian Prairie Spring (CPS), Canadian Western Amber Durum (CWAD), CW Hard White Spring (CWHWS), CW Red Spring (CWRS), CW Soft White Spring (CWSWS), and General Purpose (GP). Data were analyzed as a randomized complete block design and cultivars were nested within market class. Pearson correlation was used to determine correlations. Significance level was P ≤ 0.05. The starch digestibility range and wheat class rankings were: proximal jejunum: 23.7 to 50.6% (CWHWSc, CPSbc, CWSWSbc, CWRSab, GPa, CWADa); distal jejunum: 63.5 to 76.4% (CWHWSc, CPSbc, CWSWSbc, CWRSab, GPa, CWADa); proximal ileum: 88.7 to 96.9% (CWSWSc, CPSbc, CWHWSbc, CWRSb, GPb, CWADa); distal ileum: 94.4 to 98.5% (CWSWSb, CWHWSb, CPSb, CWRSab, GPab, CWADa); excreta: 98.4 to 99.3% (CPSb, CWRSb, CWHWSb, CWSWSab, GPab, CWADa). Wheat class affected wheat AMEn with levels ranging from 3,203 to 3,411 kcal/kg at 90% DM (CWRSc, CWSWSc, CPSb, GPb, CWADa, CWHWSa). Significant, but low positive correlations were observed between in vitro and in vivo starch digestibility, but no correlations were found between AMEn and starch digestibility. In conclusion, rate and extent of starch digestibility and AMEn were affected by western Canadian wheat class, but starch digestibility did not predict AMEn. Key Words: energy retention, slowly digestible starch, rapidly digestible starch 55   Profile of synthesized versus preformed n-3 fatty acids in chicken egg, liver and adipose tissue and the expression of genes associated with hepatic lipid metabolism. Neijat Mohamad*, Peter Eck, and James D. House, University of Manitoba, Winnipeg, MB, Canada. Dietary sources of omega-3 polyunsaturated fatty acids (n-3 PUFA), including α-linolenic acid (ALA) and preformed long-chain PUFA (LCPUFA, primarily docosahexaenoic acid, DHA), differ in their egg LCPUFA enrichment efficiency. However, mechanisms leading to these differences are unclear. To this end, the amount and distribution of n-3 PUFA in different lipid classes, including triacylglycerol (TAG) and total phospholipid (PL) in yolk, liver and adipose, as well as the expression of key hepatic enzymes in lipid metabolism were evaluated in laying hens in response to changes in dietary supply. Seventy Lohmann LSLclassic hens (n = 10/treatment) consumed either a control diet containing 0.03% total n-3 PUFA, or the control supplemented with 0.36, 0.77, and 1.19 g/100 g feed of flaxseed oil or 1.00, 2.18, and 3.36 g/100 g feed of DHA-Gold from either flaxseed oil or DHA-Gold, as sources of ALA (precursor) or DHA (preformed), respectively; each corresponding

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level supplying 0.20, 0.40, and 0.60% total n-3 PUFA. The study was arranged in a completely randomized design, and data were analyzed using the Proc Mixed procedure of SAS. ALA accumulated in a dosedependent manner (P < 0.0001) in total and lipid classes of yolk, liver, and adipose (TAG only) for ALA- and DHA-fed hens. Unlike flaxseed oil, preformed DHA contributed to greater (P < 0.0001) accumulation of LCPUFA in total PL and TAG pool of yolk, and adipose TAG. This may have been due to the elevated (P < 0.0001) expression of fatty acid activation gene, acyl-CoA synthetase (ACSL1). There was no difference in the level of eicosapentaenoic acid (EPA) incorporated in the liver total lipids between the flaxseed oil or DHA-Gold treatments; EPAliver = 2.1493x – 0.0064; R2 = 0.70, P < 0.0001 (combined data). The latter result may indicate that the levels of EPA in the liver could be involved in the regulation of LCPUFA metabolism in laying hens. Key Words: egg yolk and tissues, fatty acid profile, flaxseed oil, DHA-Gold, gene expression 56   Dietary n-3 fatty acids did not attenuate performance during sustained inflammation on commercial broilers. Julianna Jespersen*1, Isa Ehr1, Cheryl Morris1, Brian Kerr2, Anna Johnson1, Nicholas Gabler1, and Elizabeth Bobeck1, 1Iowa State University, Ames, IA, 2USDA-ARS, Ames, IA. Dietary n-3 fatty acids (omega-3) have been shown to attenuate inflammatory processes and improve health. Therefore, utilizing a lipopolysaccharide (LPS) challenge model, our objective was to assess the beneficial effects of dietary n-3 flaxseed and fish oils on broiler performance. Commercial broilers were fed either (1) a basal control diet (no supplemented n-3); (2) basal diet + flaxseed oil (4% total n-3 consisting of α-linolenic acid); or 3) basal diet + fish oil (4% total n-3 consisting of eicosapentaenoic acid and docosahexaenoic acid) for a 4-wk (6–34 d of age) enrichment period followed by a 8-d LPS challenge (3 × 2 factorial). The LPS challenge was administered by injections of either LPS (Escherichia coli 0111:B4) or sterile saline administered 4 times in total (1 mg/kg BW every 48 h, with 20% increasing dosage from 35 to 42 d of age). Treatments were assigned in a randomized complete block design with pen as the experimental unit (2 male Ross broilers/pen) with 10 replicates. All broilers were offered feed and water ad libitum. Broiler body weight (BW) and feed intake (FI), feed conversion ratio (FCR), and average daily gain (ADG) over the 8 d LPS challenge was analyzed for the interaction (diet × LPS) or the main effects (diet and LPS). Means were then separated using Tukey’s test (P ≤ 0.05). Body weight was different at the start of the challenge (P < 0.01); therefore, it was used as a covariate. No interactions were observed (P > 0.05). There was no Diet effect on any measures (P ≥ 0.15). Saline broilers had heavier BW (P < 0.01) and greater FI (P < 0.01) than the LPS-challenged broilers.

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Additionally, ADG was reduced (P < 0.01) in LPS challenged broilers, resulting in poorer FCR (P < 0.01) compared with the saline broilers. In conclusion, flax and fish oil did not attenuate LPS-induced changes in broiler performance. However, repeated challenges with LPS over an 8-d period reduced broiler growth and feed intake, and attenuated feed efficiency compared with the saline control broilers. Key Words: broiler chicken, lipopolysaccharide, n-3 fatty acid, inflammation 57   Effect of fat application site and percentage fines on feed manufacturing characteristics, broiler live performance, and carcass parts yield. .Jeffrey T. Pope*, Adam C. Fahrenholz, and John T. Brake, Prestage Department of Poultry Science, North Carolina State University, Raleigh, NC. The effects of 2 fat application sites and 2 percentage fines when fed from 16 to 44 d of age on feed manufacturing, broiler live performance, and broiler carcass yield were studied. The effect of pellet quality entering a post-pellet liquid application (PPLA) system was also studied. Each bird was fed 908 g of a common crumbled broiler starter before transitioning onto one of 5 dietary treatments. The experiment was a randomized complete block 2 × 2 design with one additional treatment to study the effect of pellet quality entering a PPLA system. The fat application sites used were in the mixer (MAF) and PPLA. The percentage added fines used were 0 and 30%. Fines were initially separated by screening the pelleted feed. Thus, there were initially 4 treatments MAF-0, MAF-30, PPLA-0, and PPLA-30. With the PPLA-30 treatment, 2 mixing methods were used to generate a fifth treatment. One PPLA-30 treatment had fat added to a mixture of pellets and fines and the fifth treatment had fat partitioned to the pellets and fines separately before recombining to make the complete diet. The dietary treatments were assigned to 40 mixed-sex pens of 8 males plus 8 females resulting in 8 replicate pens per treatment. BW and feed consumption were determined at 14, 28, 35, and 42 d of age and feed conversion ratio (FCR) was calculated on the respective days. At 44 d, 2 males and 2 females that represented the house average BW were selected from each pen for carcass yield and weights of gizzard and proventriculus. PPLA fines had significantly more energy and crude fat than PPLA pellets (P0.05). Females consuming PPLA-30 diets were significantly heavier than females consuming MAF-30% diets (P0.05). We concluded that fat laden fines improved performance of the birds coming to the feeder after many of the pellets had been consumed. Key Words: fat application site, pellet quality, percentage fines, feed manufacturing

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