Hubbard Broiler Chicks Research Articles

The Influence of Exogenous Multienzyme Preparation and Graded Levels of Digestible Lysine in Sunflower Meal-Based Diets on the Performance of Young Broiler Chicks Two Weeks Posthatching

The study was conducted to investigate the effect of adding multienzyme preparation (Rovabio Excel AP, Adisseo Asia Pacific Pte Ltd., Singapore) at 2 inclusion levels of sunflower meal (SFM; 20 and 30% of the diets) with 3 levels of digestible Lys (0.8, 0.9, and 1.0%) with and without enzyme in a 2 × 2 × 3 factorial arrangement. Each diet was offered to 4 replicates of 51 one-day-old straight-run Hubbard broiler chicks (n = 2448) in a practical vegetable-based mash diet having 2,750 kcal of ME/kg and 19% CP during 2 wk posthatching (1 to 14 d of age). Feed formulation was based on digestible amino acids, which were calculated from the CP and DM contents of each ingredient using AminoDat 2 (Degussa Corp., Allendale, NJ). The enzyme used in this study was authenticated by the supplier to have minimum level of endo-1,4-β xylanase (22,000 visco units/g) and endo-1,3(4)-β glucanase (2,000 AGL units/g) and was added at the rate of 50 mg/kg of finished diet. No significant effect of enzyme or level of SFM was observed on BW gain (BWG), feed intake, or mortality during the experimental period. The BWG and feed:gain for birds fed on 30% SFM with enzyme were comparable to those fed on 20% SFM without enzyme during 1 to 14 d of age. However, enzyme at 20% SFM depressed the BWG (P ≤0.006) and feed conversion ratio (P ≤0.027). A quadratic (P ≤0.036) response of digestible Lys was noted for BWG, whereas it was linear (P ≤0.001) for feed:gain during 1 to 7 and 1 to 14 d. A level of 1.0% digestible Lys was observed best for BWG and feed:gain. For BWG, 0.8 and 0.9% digestible Lys was comparable when it was used at 30% SFM, along with enzyme. In conclusion, enzyme supplementation during 2 wk posthatching has no remarkable effect when used in SFM-based diets. Moreover, digestible Lys may be lowered to 0.8% during the first week but not less than 1.0% during the second week post-hatching.

Effect of Lacquer (Rhus verniciflua) Supplementation on Growth Performance, Nutrient Digestibility, Carcass Traits and Serum Profile of Broiler Chickens

This experiment was conducted to explore the efficacy of lacquer (Rhus verniciflua) supplementation on growth performance, nutrient digestibility, carcass traits and serum biochemical values in commercial broilers. Eight hundred and forty Hubbard broiler chicks (1d old) were randomly distributed and allotted to four dietary treatments for five weeks. Each treatment had 5 replicates with 42 birds each. The dietary treatments were (1) control (2) 1% lacquer, (3) 2% lacquer and 4) 4% lacquer supplied as meal in the diet. Supplementation with lacquer improved weight gain (p = 0.0960) showing a linear trend during the starter phase (0-3 wk), but weight gain, feed intake and feed conversion ratio remained unaffected at the finisher phase (4-5 wk) and overall (0-5 wk). The nutrient digestibility studies conducted after 18 and 35 days of experimental feeding showed a linear (p<0.05) increase in digestibility of CP and ether extract at both measurement timess. The carcass studies were conducted on two birds per replicate (10 per treatment) at the end of both 3 and 5 wk. The dressing percentage, liver weight, heart weight, abdominal fat and the breast meat expressed as a percentage of live weight, did not differ significantly due to treatments at both phases. The serum cholesterol and high-density lipoprotein (HDL) showed a linear decrease (p = 0.0683 and p = 0.0322, respectively) as the level of supplementation increased at 3 wk; at 5 wk serum cholesterol, HDL and triglyceride levels decreased significantly showing a positive linear effect of lacquer on fat metabolism. The meat color values such as lightness, redness and yellowness did not reveal any significant trend. Overall, it could be concluded that lacquer supplementation at higher levels did not affect growth performance, but had a positive impact on fat metabolism by influencing fat digestibility and reducing serum cholesterol and triglyceride. (Asian-Aust. J. Anim. Sci. 2006. Vol 19, No. 3 : 418-424)

Effect of Varying Levels of Energy and Protein on Live Performance and Carcass Characteristics of Broiler Chicks

An experiment involving 270 straight run one-day-old Hubbard broiler chicks was conducted on floor pens to investigate the effect of different levels of energy and protein on live performance and carcass responses of broilers chicks. Six broiler starter diets with two levels of metabolizable energy (ME) i.e., 2800 and 3000kcal/kg each with three levels of crude protein (CP) i.e., 20, 21 and 22% were offered to birds from hatching to 28d of age. Similarly, six broiler finisher diets with two levels of ME i.e. 3000 and 3200kcal/kg and 3 levels of CP i.e. 16, 17 and 18%, and 18, 19 and 20%, respectively, were offered during 29-42d of age. The chicks were randomly divided into 18 replicate of 15 chicks each and there were 3 replicates under each diet. Feed intake was significantly (p<0.05) high in diet having low ME during both phase, with 20 and 22% CP during starter phase whereas all CP levels showed non-significant effects on feed intake at finisher phase. Low ME and high CP diets showed high feed intake (p<0.05) during starter and finisher phases. Higher weight gains (p<0.05) were observed at low ME diets during the experiment. Dietary CP contents at low ME did not affect the weight gain during starter phase whereas high CP with low ME showed high weight gain in finisher phase. The response of CP and ME was similar for good feed conversion ratio (FCR) as was observed for feed intake and weight gain. No significant differences of dietary treatments were observed on any of the carcass characteristics. From the recent study, it is obvious that low ME and high CP diets promised optimum performance for broiler chicks at both starter and finisher phases.

Preliminary Study on Tomato Pomace as Unusual Feedstuff in Broiler Diets

The objective of this study was to evaluate the tomato pomace (TP) as unusual feed stuff in broiler diets in terms of growth, feed conversion ratio (FCR) and mortality. 300-day old Hubbard broiler chicks were weighed and randomly distributed into 4 groups with three replicates of 25 chicks each. Birds were fed four experimental diets in which the first was the control group (T1) and the other diets contained 10% alkali treated tomato pomace (T2), 10% heat-treated tomato pomace (T3) and 10% sun dried tomato pomace (T4). All diets were isonitrogenous and isocaloric. Feed and water were offered ad-lib during the experiment period. The results of this experiment showed that there were no significant differences (P<0.05) in live body weight due to feeding chicks diets containing TP. The only significant difference (P<0.05) was observed between the control group and those fed dietary treatments. Body weight gain had nearly the same trend as live body weight. Cumulative feed consumption was significantly (P<0.05) affected by feeding TP whe n compared with control group. There were no significant differences (P<0.05) in FCR of chicks fed different dietary treatments when compared with those fed control diets. Mortality rate was 3% during the whole experiment period, which is insignificant.

Effect of Enzyme Supplementation on the Performance of Broiler Finisher Fed Microdesmis puberula Leaf Meal

A thirty-five day feeding trial was conducted to evaluate the performance of broiler finishers fed Microdesmis puberula leaf meal supplemented with Safzyme (a cellulolytic enzyme). Microdesmis R puberula is a choice tropical browse plant. Three broiler finisher diets were formulated to contain 0.0, 12.5% Microdesmis puberula leaf meal without enzyme. and 12.5% Microdesmis puberula leaf meal with 0.10% enzyme. One hundred and twenty (120) four-week-old Hubbard broiler chicks were divided into three groups of forty (40) birds each and randomly assigned to the three treatment diets in a completely randomized design (CRD). Data were collected on feed intake, body weight gain and feed conversion ratio. There was significant difference (p 0.05) from birds on leaf meal diets without enzyme supplementation. Birds on 0.0% leaf meal diet recorded the highest daily body weight gain. Feed conversion ratios of all treatment groups were comparable. The result suggests that 0.10% of the enzyme supplementation in diets containing 12.5% Microdesmis puberula leaf meal did not improve the performance of finisher broilers.

Evaluation of &lt;i&gt;Microdesmis puberula&lt;/i&gt; leaf meal as feed ingredient in broiler starter diets

A 21- day feeding trial was conducted to evaluate the leaf meal of Microdesmis puberula as feed ingredient in broiler starter diets. Microdesmis puberula is a preferred tropical browse plant. The leaves were harvested, chopped to facilitate drying, spread evenly in a room for four days until the material become crispy while still retaining it's greenish colouration. The material was milled using a hammer mill to produce the leaf meal. Microdesmis puberula leaf meal contain 17.32% crude protein, 6.52% ether extract, 12.25% total ash, 24.84% crude fibre, 24.06% NFE and an appreciable percent of minerals. Three broiler starter diets were formulated to contain the meal at dietary levels of 0%, 5% and 10%. One hundred and eighty (180), 14 –day old hubbard broiler chicks were divided into three groups of sixty birds each and randomly assigned to the three treatment diets in a completely randomized design (CRD). Data were collected on feed intake, body weights and feed conversion ratio. There were significant (P

Preliminary Observations on the Nutritive Value of Toad Meal in Broiler Starter Diets

A 21-day feeding trial was conducted to determine the nutritive value of toad meal as protein supplement in broiler starter diets. Live toads were harvested from different ponds, knocked unconscious with a metal rod, eviscerated to remove the offals and later smoke-dried at a temperature of 40 ºC for 3 days. They were crushed and milled to produce toad meal (TM). Toad meal contained 59.06% crude protein, 10.50% either extract, 12.7% total ash, 5.61% crude fibre and 5.24 kcal/g GE. Three broiler starter diets were formulated such that they contained toad meal (TM) at 0%, 5% and 10% respectively. Three hundred, 14-day old Hubbard broiler chicks were divided into three groups of hundred birds each and randomly assigned to the three treatment diets in a completely randomized design (CRD). Each treatment was replicated four times, giving 25 birds per replicate. Data were collected on feed intake, body weight gain, fed conversion ratio and internal organ analysis. There was no significant (P

Níveis de lisina para frangos de corte de 1 a 21 e 15 a 40 dias de idade

Foram realizados dois experimentos para determinar a exigência nutricional de lisina total para frangos de corte Hubbard e Ross de ambos os sexos, nos períodos de 1 a 21 e 15 a 40 dias de idade. Foram avaliados ganho de peso, consumo de ração, conversão alimentar e rendimentos de carcaça, peito com osso, carne de peito e gordura abdominal. Para cada fase, o delineamento experimental utilizado foi em blocos casualizados, em esquema fatorial 2 x 2 x 6, constituído de dois sexos, duas marcas e seis níveis dietéticos de lisina, com quatro repetições e um total de 1920 aves. Dietas basais com 1,0% de lisina, 22,61% PB, 3050 kcal EM/kg, no primeiro experimento, e 0,825% de lisina, 19,6% PB e 3200 kcal EM/kg, no segundo experimento, foram suplementadas com seis níveis de lisina (0; 0,06; 0,12; 0,18; 0,24; e 0,30%). Considerando-se características como ganho de peso e conversão alimentar, as estimativas das exigências dietéticas para a fase de 1 a 21 dias foram 1,191 e 1,198% de lisina total para machos e fêmeas Ross e de 1,174 e 1,188% de lisina total para machos e fêmeas Hubbard, respectivamente. Para a fase de 15 a 40 dias, considerando-se ganho de peso, consumo de ração, conversão alimentar e rendimentos de carcaça, peito com osso, carne de peito e gordura abdominal, o nível de 1,125% de lisina total na ração foi considerado adequado para ambos os sexos das duas marcas comerciais.

Toxicological evaluations of cyclopiazonic acid and ochratoxin A in broilers

The individual and combined effects of ochratoxin A (OA) and cyclopiazonic acid (CPA) were evaluated in Petersen x Hubbard broiler chickens from 1 d to 3 wk of age. The experimental design was a 2 x 2 factorial with treatments of 0 and 2.5 mg OA/kg feed and 0 and 34 mg CPA/kg feed. Production performance, serum biochemistry, and gross pathological observations were evaluated. Body weight gain was reduced (P < 0.05) by OA, CPA, and OA-CPA in combination at the end of 3 wk. Ochratoxin A significantly increased the relative weight of the kidney and serum concentrations of uric acid and triglycerides and decreased total protein, albumin, and cholesterol. The toxicity of CPA was expressed primarily through increased relative weights of the proventriculus and increased activity of creatine kinase. Exposure to OA-CPA was characterized by increased relative weights of the liver, kidney, pancreas, and proventriculus; decreased concentrations of serum albumin, total protein, and cholesterol; increased activity of creatine kinase; and increased concentrations of triglycerides and uric acid. Postmortem examination revealed that the chickens fed CPA or OA-CPA had thickened mucosa and dilated proventricular lumen. Data from this study demonstrate that OA, CPA, and the OA-CPA combination can limit broiler performance and adversely affect broiler health. The interaction of the compounds was primarily additive or less than additive in the parameter in which the interaction occurred.

Pathogenicity of Salmonella Enteritidis Phage Types 4, 8, and 23 in Broiler Chicks

Four hundred fifty day-old Hubbard broiler chicks were subdivided into 15 groups of 30 chicks each. Six groups of chicks received 0.5 ml of broth culture containing 5 x 10(6) colony-forming units (CFU) of Salmonella enteritidis (SE) phage types (PTs) 4, 8, and 23 by crop gavage. Similarly, six other groups received 0.5 ml containing 5 x 10(8) CFU of SE. One group was inoculated with 0.5 ml containing 5 x 10(6) CFU of Salmonella pullorum, and another group received 0.5 ml containing 5 x 10(8) CFU of S. pullorum. A group of 30 chicks were kept as uninoculated controls. Chicks were observed daily for clinical signs and mortality. All birds were weighed at 7, 14, and 21 days postinoculation 21 (DPI). Four chicks were randomly selected from each treatment group, euthanatized, and necropsied at 7 and 14 DPI. Gross lesions were recorded and selected tissues were collected for histopathology. The higher rates of illness and mortality were observed in chicks inoculated with 5 x 10(6) and 5 x 10(8) CFU of S. pullorum, followed by SE PT4 of human origin and SE PT4 of chicken origin. Moderate to high mortality was observed in chicks inoculated with the higher dose of SE isolates that belonged to PT8 and one SE of PT23. Variable mortality was evident in groups inoculated with the lower dose of salmonella. The most consistent gross and histopathologic changes, including fibrinous pericarditis and perihepatitis, were seen in the dead birds from various treatment groups. The lower mean body weights were present in all treatment groups compared with uninoculated controls. No illness or mortality was observed in uninoculated control groups.

Exigência de fósforo disponível e efeito da granulometria na biodisponibilidade de fósforo da farinha de carne e ossos para pintos de corte

O objetivo deste trabalho foi determinar a exigência nutricional de P disponível e o efeito da granulometria na biodisponibilidade de P da farinha de carne e ossos (FCO) para pintos de corte. Duzentos e cinqüenta e 450 pintos Hubbard de 1 a 21 dias de idade, respectivamente, foram distribuídos em delineamento inteiramente casualizado, com cinco (exigência) ou nove (biodisponibilidade) tratamentos, cinco repetições e dez aves por unidade experimental. A exigência de P foi determinada por intermédio de uma ração basal com baixo conteúdo de P (0,15% Pdis), suplementada com cinco níveis de P proveniente do fosfato bicálcico. A disponibilidade de P foi estimada por intermédio da relação dos coeficientes de regressão, considerando o P do fosfato bicálcico como 100% disponível. Os valores estimados de exigência nutricional de P disponível, determinados com o modelo descontínuo LRP, variaram de 0,311 (0,104% P disponível/Mcal EM), para ganho de peso, a 0,426% (0,142% P dis./Mcal EM), para cinza na tíbia (g). Os valores medios de disponibilidade de P obtidos para a FCO com granulometria grossa, média e fina foram 106,50; 103,56; e 121,94%, respectivamente.

Effects of Supplemental Ascorbic Acid on the Performance of Broiler Chickens Exposed to Multiple Concurrent Stressors

An experiment was conducted to determine whether ascorbic acid (AA) increases resistance of female Hubbard × Hubbard broiler chicks to multiple concurrent stressors. Stressors imposed from 10 to 17 d posthatch included 2 × 2 × 2 factorial combinations of beak trimming [(B), sham-operated or beak-trimmed and cauterized], coccidiosis [(C), gavage with 0 or 3 × 105 sporulated Eimeria tenella oocysts], and heat stress [(H), 28 vs 33 C]. A starter diet was supplemented with AA to provide 0,150, or 300 ppm (milligrams per kilogram). This resulted in a 2 × 2 × 2 × 3 factorial design with two six-chick replicates of each of the 24 treatment combinations. Data were analyzed using ANOVA and a level of 95% significance. Ascorbic acid increased feed intake and lowered plasma corticosterone and heterophil:lymphocyte ratios. Heat depressed weight gain and feed intake and elevated heterophil:lymphocyte ratios. Heat and AA interacted to improve weight gain and feed intake and lower heterophil:lymphocyte ratios. Coccidiosis depressed weight gain, feed efficiency, and heterophil:lymphocyte ratios. Coccidiosis and AA interacted to increase feed intake and lower plasma corticosterone and heterophil: lymphocyte ratios. Beak trimming increased heterophil:lymphocyte ratios. Beak trimming and AA interacted to increase feed intake and lower heterophil: lymphocyte ratios. Weight gain and feed efficiency decreased whereas heterophil:lymphocyte ratios increased linearly in unsupplemented birds as a function of stressor “order” (the number of stressors imposed simultaneously) indicating an additive effect of systematically increasing the number of stressors. No changes in feed efficiency or heterophil:lymphocyte ratios were detected as a function of stressor order when AA was provided. Ascorbic acid reduced the slope of the regression equation describing the relationship between weight gain and stressor order. It was concluded that AA, particularly at 150 ppm, enhanced performance of broiler chicks exposed to multiple concurrent environmental stressors.

Nutritive value of sausage casings from processed cattle hides

Two experiments were conducted to investigate the nutritive value of sausage casings prepared from cattle hides as a protein source for day-old hybrid (Hubbard × Hubbard) broiler chickens. The results demonstrate that sausage casings are an available protein source for broiler chicks that can be substituted for soybean meal at levels up to 8% of the feed without affecting average daily gain and feed efficiency. Key words: Sausage casings, cattle hides, broiler chickens, collagen, gelatin

Tibial Dyschondroplasia of Chickens Induced by Fusarochromanone, a Mycotoxin

Chicks were fed for 3 weeks a practical broiler starter diet amended with fusarochromanone (FC), a mycotoxin. In Hubbard broiler chicks, the highest test dose of FC (75 ppm) suppressed body weight by 33% and humoral response to sheep erythrocytes by 34% to 50%, and increased the incidence of tibial dyschondroplasia (TD) to 100%. The intermediate dose (35 ppm) significantly increased the incidence of TD in both types of broiler chicks (Hubbard and Indian River), but its effect on humoral response to sheep erythrocytes was not consistent across several experiments. A minimum dietary concentration greater than 20 ppm was required to significantly increase the incidence of TD. Excessive dietary copper or zinc (200 ppm) alleviated the effect of FC on TD. However, activities of copper-dependent ceruloplasmin and superoxide dismutase was not affected by FC. Cartilage mineral profiles in FC- or Thiram-induced TD differed from that of 1-day-old hypertrophic embryonic cartilage core (less K and Mn). FC did not induce TD in leghorn chicks.

Effect of Virginiamycin and Monensin Interaction onSalmonellaInfected Chicks

Abstract Kamel, F. M., Azzam, A. H. and Abd El-Aziz, M. I. 1993. Effect of virginiamycin and monensin intraction on Salmonella infected chicks J. Appl. Anim. Res., 3: 47–54. Hubbard broiler chicks were used to study the effect of virginiamycin and monensin in a dose of 20 and 120 ppm respectively for 45 successive days on occurence of salmonella in experimentally infected chicken. Simultaneously serum glutamic oxalacetic (SGOT), serum pyruvic transaminases (SGPT), alkaline phosphatase (AP) activities; total protein, A/G ratio; urea and creatinine as well as the withdrawal period of monensin were estimated. Lower caecal salmonella counts were noticed in chicken treated with either monensin or virginiamycin. than those fed on a ration supplemented with their combination. Elevation of SGPT, AP activities and A/G ratio in birds fed on monensin mixed ration was observed. No significant change was seen in level of urea in all treated groups. However, level of serum creatinine significantly increased in birds treated with monensin alone and in combination with virginiamycin. Higher monensin concentration was detected in liver and kidney and persisted for 96 and 120 hours respectively.

Toxicological Evaluation of Aflatoxin and Cyclopiazonic Acid in Broiler Chickens

The individual and combined effects of aflatoxin (AF) and cyclopiazonic acid (CPA) were evaluated in day-old Petersen × Hubbard broiler chickens to 3 wk of age. Treatments were arranged in a 2 × 2 factorial with levels of 0 and 3.5 mg AF/kg of feed, and 0 and 50 mg CPA/kg of feed. Production performance, serum biochemistry, and gross pathological observations were evaluated. Body weight gain was significantly (P < .05) reduced by AF, CPA, and the AF-CPA combination at the end of 3 wk. Aflatoxin significantly increased the relative weight of the kidney and serum concentration of blood urea nitrogen and decreased serum concentrations of protein, albumin, cholesterol, phosphorus, and the activity of lactate dehydrogenase. The toxicity of CPA was expressed through increased relative weights of the liver, kidney, and proventriculus, increased levels of uric acid and cholesterol, and decreased serum phosphorus. The activity of AF-CPA combination was characterized by increased relative weight of the liver, kidney, pancreas, and proventriculus, decreased concentrations of serum albumin and phosphorus, increased concentrations of serum glutamic oxalacetic transaminase and blood urea nitrogen, and decreases in the relative weight of the bursa of Fabricius. Post-mortem examination revealed that the chickens fed CPA and the AF-CPA combination had thickened mucosa and dilated proventricular lumens, hard fibrotic spleen, and atrophy of the gizzard. The data from the present study demonstrate that both AF and CPA alone and the AF-CPA combination can limit broiler performance and adversely affect broiler health. In most cases the effects of AF and CPA were additive.

Diclazuril, a New Broad Spectrum Anticoccidial Drug in Chickens.: 1. Dose Titration Studies and Pilot Floor Pen Trials

Diclazuril, a new anticoccidial drug, was tested in poultry against six Eimeria species either in single species infections in dose titration studies or in mixed species infections in floor pen trials. The dose titration studies in cockerels indicated that diclazuril at dosages of 10, 5, 1, and .5 ppm was highly active against all major pathogenic species: E. tenella, E. acervulina, E. necatrix, E. brunetti, E. maxima, and E. mitis and effective in terms of weight gain and suppression of mortality, dropping scores, and oocyst counts.In two floor pen trials diclazuril was fed for 6 wk to broiler chickens experimentally infected either with E. tenella and E. acervulina or with E. necatrix and E. brunetti. Dose levels of 10, 5, and 1 ppm suppressed mortality and lesion scores. Even at 1 ppm the mean terminal body weight, feed conversion, and productivity index of treated birds were comparable to results for the uninfected, unmedicated controls. In these pilot studies, involving 1,020 Hisex and 1,000 Hubbard broiler chickens, it has been demonstrated that diclazuril at the dose level of 1 ppm in the diet is an excellent anticoccidial without any adverse effects.

Early prediction of performance in broilers: relationship between length of tarsometatarsus and weight gain.

Two groups, each of 25 Hubbard broiler chicks, were individually raised in cages for 49 d. The tarsometatarsus length at 1-d old and finishing point, food utilisation and finishing body weight were recorded and statistically analysed. Birds with long tarsometatarsi at 1-d old were found to have significantly (P less than 0.001) greater finishing body weights than those with short tarsometatarsi at 1-d old. A strong correlation (r = 0.80) was found between length of tarsometatarsus at 1-d old and body weight at 49 d. Length of tarsometatarsus at 1-d old is thus a possible basis for predicting body weight gain.

The Effect of Feeding Four Fish Hydrolyzate Meals on Broiler Performance and Carcass Sensory Characteristics

Hubbard broiler chicks were fed to 7 weeks of age diets containing hake (Pacific whiting), Dover sole, Brown rock, and Atlantic cod hydrolyzate meal to provide 4.3% crude protein in diets and herring meal to provide 4.9% crude protein in the diet (dry matter basis). No significant differences were observed among the treatments in live body weight and feed conversion; however, mean dressed broiler weight (P<.05) was influenced by the type of fish meal. The diets affected drip cooking loss (P<.05) and the fishy and off-flavor sensory characteristics of the cooked broiler carcasses. There were no differences (P>.05) due to diet in total cooking losses, cooking time, total moisture, and juiciness.

Toxic Effects of Aflatoxin B 1 in Chickens Given Feed Contaminated with Aspergillus flavus and Reduction of the Toxicity by Activated Charcoal and Some Chemical Agents

Aspergillus flavus NRRL 3357 was grown on enriched long-grain rice for 7-10 days to produce aflatoxin B1 (AFB1). The quantity of AFB1 in moldy rice was determined by thin-layer chromatography using ultraviolet light. When the dried moldy rice powder was fed to day-old Hubbard X Hubbard broiler chicks in unmedicated feed (AFB1 level 10 ppm) for 8 weeks, there was a profound reduction in weight gain and feed consumption. Chickens fed AFB1 developed severe liver damage, as determined by the concentration of hepatic microsomal cytochrome P-450 and by the activities of microsomal benzphetamine N-demethylase and serum glutamic oxalacetic transaminase. However, activated charcoal, reduced glutathione, cysteine, selenium (as sodium selenite), beta-carotene, and fisetin administered orally considerably reduced the toxicity of AFB1 in the experimental chickens.