2Â·84% AFG1 and 1Â·12% AFG2)/kg diet on growing Japanese quail chicks ... 40 Japanese quail chicks were divided into 4 treatment groups (control, AF, CLI, ...
British Poultry Science (1999) 40: 495–500
Effect of clinoptilolite on performance of Japanese quail (Coturnix coturnix japonica) during experimental aflatoxicosis È . YILDIZ AND H. OGÏ UZ1 S.S. PARLAT, A.O Department of Animal Science, and 1Department of Pharmacology and Toxicology, University of Selc¸uk, Konya, Turkey Abstract 1. Clinoptilolite (CLI, a natural zeolite), incorporated into the diet at 50 g/kg, was evaluated for its ability to reduce the deleterious effects of 2·0 mg total aflatoxin (AF;83·06% AFB 1, 12·98% AFB 2, 2·84% AFG1 and 1·12% AFG2)/kg diet on growing Japanese quail chicks from 10 to 45 d of age. A total of 40 Japanese quail chicks were divided into 4 treatment groups (control, AF, CLI, AF plus CLI) each consisting of 10 chicks. The performance of the birds was evaluated. 2. The AF treatment significantly decreased food consumption and body weight gain from the 3rd week onwards. The adverse effect of AF on food conversion ratio was also significant from week 4 of the experiment. 3. The addition of CLI to an AF-containing diet significantly reduced the deleterious effects of AF on food consumption, body weight gain and food conversion ratio. Food consumption was reduced by 14% in quail chicks consuming the AF diet without CLI, but by only 6% for quail chicks consuming the AF plus CLI diet. Similarly, overall body weight gain was reduced by 27% in birds consuming the AF diet without CLI, but by only 8% for birds consuming the AF plus CLI diet. 4. The addition of CLI to the AF-free diet significantly decreased food consumption and body weight gain during week 4, but these parameters were similar to the controls in week 5. No mortality was observed in any of the groups. 5. These results suggest that CLI effectively diminished the detrimental effects of AF on the variables investigated in this study.
INTRODUCTION Aflatoxins (AF), natural contaminants of foodstuffs, are toxic metabolites produced by Aspergillus flavus and Aspergillus parasiticus (Giambrone et al., 1985; Demet et al., 1995). Aflatoxicosis is an important disease of livestock and poultry. The occurrence of AF in foodstuffs of domestic animals and poultry is quite common in many countries (Arafa et al., 1981). AF affect chickens, turkeys, quail, ducklings and goslings. AF may be produced in food and foodstuffs before harvest and also during storage under certain conditions of humidity and temperature (OgÏuz, 1997). Four types of AF are produced: AFB1, AFB2, AFG1 and AFG2 (Pier, 1992). The prevalence of toxic amounts of AF in foods, intensive poultry production methods and high density diets increases the likelihood that growing chicks may be exposed to AF-contaminated food (Arafa et al., 1981; Harvey et al., 1993). AF affect different species in different ways but aflatoxicosis in poultry is characterised by listlessness, anorexia with lowered growth rate, poor food utilisation, decreased weight gain, decreased egg production, increased susceptibility to environmental and microbial stresses, and increased mortality (Arafa et al., 1981). Signs of aflatoxicosis also include anaemia (Kec¸eci et al., 1998), inhibition of immune
function (Campbell et al., 1983; C ¸ elik et al., 1995), hepatotoxicosis (OgÏuz, 1997; Kiran et al., 1998), mutagenesis, teratogenesis, carcinogenesis, and haemorrhage (Edds and Bortell, 1983; Schull, 1985). For that reason, AF are a potential threat to poultry health and cause severe economic losses in the poultry industry (Kaya, 1984). When various poultry species were fed on diets with different concentrations of AFB1 (0·7, 1·4 and 2·1 mg/kg) poults and goslings appeared to be the most sensitive, quail were most vulnerable, while domestic chicks were most resistant (Arafa et al., 1981). In the same study, quail chicks receiving 0·7 mg/kg consumed significantly less food during the 2nd week, but 2·1 mg/kg was necessary to reduce food intake significantly during the 3rd week. Studies performed on AF-resistant Japanese quail lines showed that plasma protein and lipid concentrations and liver protein and lipid contents of birds were higher than those in AF-sensitive lines (Pegram et al., 1986). In a previous experiment, laying Japanese quail receiving 2 and 4 mg/kg dietary AF had decreased food conversion ratio (Sawhney et al., 1973). A significant decrease in body weight gain was found in Japanese quail fed on 2·5 mg/kg AF-contaminated diet for 3 weeks (Ruff et al. 1992). Johri et al. (1989) investigated the effects
Correspondence to: H. OgÏuz, Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Selc¸uk, 42031, Kampu¨s, Konya, Turkey. Accepted for publication 5th February 1999. ISSN 0007–1668 (print)/ISSN 1466–1799 (online)/99/040495– 06 © 1999 British Poultry Science Ltd
S.S. PARLAT ET AL.
of low dietary AF (lower than 0·75 mg/kg diet) in Japanese quail fed on toxic diets for 100 d. Food consumption and hatchability of fertile eggs were adversely affected by 0·3 mg/kg diet. Feeding of AFB1 at the rate of 0·5 mg/kg to young Japanese quail resulted in a significant decrease in body weight gain that became apparent in the 3rd week (Sadana et al., 1992). Removing AF from contaminated food and foodstuffs remains a major problem and there is a great demand for effective decontamination technology. Decontamination procedures have focused on degrading, destroying, inactivating or removing AF by physical, chemical or biological methods. A successful detoxification process must be economical, must be capable of eliminating all traces of toxin without leaving harmful residues and must not impair the nutritional quality of the commodity (Leeson et al., 1995). Large-scale, practical, and cost-effective methods for detoxifying AF-containing foodstuffs are currently not available although a variety of methods for detoxifying AF have been employed with limited success. Also, the stability of AF to heat and other physical conditions limits the use of these inactivation processes. Therefore, the use of AF-contaminated food remains a significant problem, and one of the serious economic implications (Jindal et al., 1994; Pasteiner, 1994). An encouraging approach to the problem has been to use non-nutritive and inert adsorbents in the diet to bind the AF and reduce their absorption from the gastrointestinal tract. These compounds must not be absorbed from the gastrointestinal tract and must have the ability to bind physically with chemical substances, precluding their absorption (Kubena et al., 1990; Winfree and Allred, 1992; OgÏuz, 1997). Clays and zeolites have been used for this purpose. These are generally inert and non-toxic to animals (Olver, 1997) and have a capacity to bind AF (Phillips et al., 1988). The dietary addition of zeolites (Harvey et al., 1993; Scheideler, 1993; Kec¸eci et al., 1998), bentonite (Araba and Wyatt, 1991; Winfree and Allred, 1992; OgÏuz, 1997) and hydrated sodium calcium aluminosilicate, a natural phyllosilicate (Kubena et al., 1993a,b) and activated charcoal (Jindal et al., 1994) have been used for the reduction of AF toxicity in chickens. Similar adsorbents have been used in turkeys (Kubena et al., 1991), ducks (Sjamsul et al., 1990), rats (Pietri et al., 1990; Voss et al., 1993), cows (Veldman et al., 1992), lambs (Harvey et al., 1991) and pigs (Lindeman et al., 1993). A protective effect against AF was observed in most of the experiments. Zeolites are crystalline, volcanic, hydrated aluminosilicates of alkali and alkaline earth cations, with infinite, 3-dimensional structures (Waldroup et al., 1984; Elliott and Edwards, 1991). Both the ion exchange and absorption properties of natural zeolites make far more efficient use of dietary nitrogen by animals (Olver, 1997). Clinoptilolite
(CLI, a natural zeolite), occurs as laths and plates, many of which display the characteristic tubular morphology typical of basalt-vug heulandite. The laths are commonly 1 to 3 µm in thickness and 5 to 20 µm in length. CLI also is known to occur in almost anhedral masses (Ming and Mumpton, 1989). Harvey et al. (1993) investigated the effects of CLI (5 g/kg diet) on aflatoxicosis (3 mg/kg diet) in broiler chicks for 3 weeks. Results of the study demonstrated that adding CLI alone to the diet did not adversely affect the health or performance of broiler chicks. Addition of CLI to an AF-contaminated diet did not significantly diminish the toxicity of high concentrations of AF (3·5 mg/kg diet) to growing broiler chicks. However, another natural zeolite (mordenite) significantly diminished the toxicity of AF. Dwyer et al. (1997) tests CLI (10 g/kg diet) for reduction of the effects of cyclopiazonic acid (45 mg/kg diet) in broiler chicks. The treatment did not effectively diminish the cyclopiazonic acid toxicity in chicks. No experimental study dealing with reduction of AF toxicity in Japanese quail has been found. The objective of the present study was to determine whether CLI could protect against the toxic effects of AF on the growth of Japanese quail during experimentally induced aflatoxicosis. MATERIALS AND METHODS Forty 10-d-old, unvaccinated Japanese quail chicks of both sexes (5 male and 5 female for each group) were individually placed in heated batteries. Individualy weighed chicks were divided at random into 4 groups, each of 10 birds. The quail received a basal diet (24 g/kg crude protein; 12·1 MJ ME/kg) formulated to contain the National Research Council (1994) requirements of all nutrients, without added antibiotics, coccidiostats, or growth promoters. Diet and water were always available and lighting was continuous. Composition of the basal diet is shown in Table 1. The basal diet was tested for possible residual AF before feeding (Howel and Taylor, 1981), and was found negative. The chicks were weighed weekly to determine gains in body weight. Food consumption was also determined weekly. Mortality was recorded as it occurred. The trial period was 5 weeks. The experimental design consisted of 4 dietary treatments: CONT: basal diet; AF: basal diet plus 2 mg AF/kg diet; CLI: basal diet plus 50 g CLI (CLI-NUT/1000, Incal Mining and Biotechnology Ltd, Izmir, Turkey)/kg diet; 4) AF+CLI: basal diet plus 2 mg AF plus 50 g CLI/kg diet. The AF was produced by the method of Shotwell et al. (1966) with minor modifications by OgÏuz (1997). Briefly, 100 g of sterile polished rice was inoculated with 1 ml of resuspended spores (1·5×106 spores/ml) of Aspergillus parasiticus NRRL 2999 (USDA, Agricultural Research Service, Peoria, IL), placed in an incubator at 28°C and fermented for
EFFECT OF CLI ON AFLATOXICOSIS
by the extraction method: 92%). The rice powder was incorporated into the basal diet to provide the desired amount of 2·0 mg AF/kg food. When the chicks reached 45 d of age, the feeding trial was terminated. Data for food consumption, body weight gains and food conversion ratio were grouped and expressed as mean±pooled standard errors of means. The results obtained were analysed statistically using Duncan’s multiple range test (SPSS, 1988). Statements of statistical significance are based on P