An alternative to antibiotic-based drugs in feed for enhancing performance of broilers grown on Eimeria spp.-infected litter.

Three trials were conducted to evaluate the effects of lasalocid, an anticoccidial feed additive (90.7 kg/ton); bacitracin, a growth-promoter (50 g/ton); and yeast culture residue (YCR) (1 kg/ton) on the performance of broiler chicks reared to 42 d of age on recycled litter. Recycled litter consisted of pine wood shavings containing droppings from chicks infected with 3 select strains of coccidia (Eimeria tenella, Eimeria maxima, and Eimeria acervulina). Response variables (BW, intestinal tract and litter coliform counts, cecal and liver relative weights, and litter moisture content) were recorded biweekly. Mean BW of chicks fed the diet supplemented with YCR was higher than that of the controls (P < 0.05) and comparable to that of the lasalocid-treated birds in all 3 trials. Mean BW of chicks in all treatment groups decreased uniformly as the litter aged and moisture content increased. The mean intestinal coliform population from YCR-treated chicks was lower (P < 0.05) than those of the control and lasalocid populations. The coliform count was consistently lower than that in chicks on a bacitracin-supplemented diet. Coliform counts from the control and lasalocid-treated birds did not differ. The litter coliform counts increased with increased use of the litter. Cecal and liver relative weights calculated from the chicks in trial 3 showed that only the liver was significantly affected by treatments. YCR appeared to be a viable alternative to bacitracin and lasalocid medication in enhancing growth of broiler chicks reared on recycled litter.

Relationship between age of commercial broiler chickens and response to photostimulation.

A study was conducted to determine the relationship between age of commercial broiler chickens and response to photostimulation. The chickens were brooded collectively for 1 wk and then separated into five light treatment groups with each group replicated three times using a completely randomized block design. After Week 1, the five light treatments applied were: 6, 5, 4, 3, and 2 wk of continuous supplementary lighting, respectively. Chickens were fed a corn-soybean meal basal diet containing 22% CP and 3,300 kcal ME/ kg of feed from day old to 7 wk. At 7 wk of age, chickens in Group 5 treated with supplementary light during the last 2 wk of growth had the highest mean BW when the data on sexes were combined. When the data were separated by sex and analyzed, only male chickens showed a significant response to photostimulation and this was observed at 4 wk of age. Chickens in Group 5 had the best feed conversion with less mortality and no leg disorders. There were no significant differences among the relative organ weights among the treatment groups except for the pancreas. The pancreas taken from Group 5 had the smallest weight relative to BW. There were no significant differences in breast, thigh, drumstick, and wing weights when expressed as relative weight. However, there were significant differences when expressed as absolute weight. The breasts taken from birds in Group 5 were significantly heavier than the control breasts.

Sensitivity of Escherichia coli O157:H7 strain 932 to selected anticoccidial drugs in broiler chicks.

The ability of selected anticoccidial drugs to inhibit the colonization of day-old male broiler chicks (Cornish Rocks) by Escherichia coli O157:H7, strain 932 was examined. Chicks were challenged with 1.8 x 10(9) E. coli O157:H7 on Day 1, and fed diets supplemented with three selected anticoccidial drugs; monensin, nicarbazin, or robenidine. The cecal and colon fecal contents of the chicks were removed on Day 7, 14, and 21 postinoculation and examined for the concentration of E. coli O157: H7 per gram of contents. Monensin effectively reduced cecal and colon colonization of the chicks by E. coli O157:H7. By Day 7, there were significant reductions in the bacterial population of the cecal contents of chicks receiving the monensin-medicated feed, and by Day 21 no E. coli O157:H7 was recovered from the cecal and colon contents. The bacterial counts in the colon contents of the nicarbazin- and robenidine-medicated and unmedicated chicks were significantly higher than the monensin-treated chicks. Bacterial populations in the colon contents were high only when there were high bacterial concentrations in the cecal contents.

The use of Saccharomyces cerevisiae to suppress the effects of aflatoxicosis in broiler chicks.

Three hundred and sixty day-old commercial broiler chicks were assigned to a 3 x 2 factorial arrangement of treatments to examine the effects of three levels of Saccharomyces cerevisiae 0, .05, and .1% of feed, and two levels of aflatoxin, 0 and 5 ppm, singly and in combination on aflatoxicosis. Each treatment group was replicated three times. The S. cerevisiae and aflatoxin were incorporated in a standard commercial broiler ration and fed to chicks for 4 wk. Data were collected weekly on body weights, and at the end of the experiment on the relative weights of the liver, proventriculus, pancreas, and heart. Serum concentrations of the albumin, total protein, cholesterol, uric acid, triglycerides, and enzyme activities of alanine transaminase, aspartate aminotransferase, lactase dehydrogenase, and creatine phosphokinase were also evaluated. Results showed that chicks receiving aflatoxin-contaminated feed had suppressed body weight (456 g), which significantly improved (516 g) with the inclusion of .1% S. cerevisiae. The relative weights of liver (3.58%), heart (.916%), and proventriculus (.770%), which increased significantly with the addition of 5 ppm of aflatoxin, were restored to 3.00, .783, and .680%, respectively, with the dietary inclusion of .1% S. cerevisiae. The serum concentrations of albumin and total protein (.66 and 1.62 g/100 mL), which were significantly decreased by aflatoxin, were elevated to .88 and 2.24 g/100 mL, respectively, with the inclusion of .1% S. cerevisiae.(ABSTRACT TRUNCATED AT 250 WORDS)

Magnesium sulfate effects on coliform bacteria reduction in the intestines, ceca, and carcasses of broiler chickens.

The objective of the study was to evaluate the effects of MgSO4 on intestinal and cecal content reduction with subsequent effects on carcass weight loss and coliform bacterial counts in the intestine and ceca, and on the processed carcass. Four hundred and eighty broiler chicks, 49 days of age, were fed MgSO4 at levels of 0, 2.5, 4.0, 5.5, 7.0, and 8.5 g/L via drinking water 24 h before processing. Samples from the intestinal and cecal contents and swabs from the processed carcass surface were plated for coliform bacteria colonization. The results indicated that carcass weight loss was not affected significantly by MgSO4, irrespective of the levels fed. The mean dressing percentage of the treated chicks was 64.9% compared with 65.2% for the controls. Although the reduction in the intestinal contents was not significant, the coliform bacterial counts declined from 1.4 x 10(6) to 1.4 x 10(4), a reduction of 2 logs when the MgSO4 was administered at 5.5 g/L. However, both the cecal contents and coliform bacteria were reduced significantly when the birds were given 5.5 g/L of MgSO4. The reduction of the coliform bacteria in the ceca was significant when compared with the control, an approximate reduction of 3 logs. Also, the bacterial counts on the carcass surface were nonsignificantly reduced from 2.2 x 10(4) to 2 x 10(3), a 1-log reduction. Correlation coefficients showed that as the contents of the intestine decreased, the coliform bacterial counts in the ceca and on the carcass surface decreased.(ABSTRACT TRUNCATED AT 250 WORDS)

Single and combination effects of administering salinomycin and aflatoxin to broiler chicks.

A factorial design (2 by 3) was used to evaluate the interaction between aflatoxin (0, 2.5, and 5 mg per kg) and salinomycin [0, 60 g per ton (909 kg)]. There were four replicates of 10 chicks per treatment. The chicks were maintained in batteries from 0 to 3 wk of age, with feed and water available for ad libitum intake. Aflatoxin at both levels (2.5 and 5 mg per kg) with and without salinomycin decreased body weight. The efficiency of feed utilization was affected only at the 5 mg per kg level of aflatoxin. Feeding 5 mg per kg of aflatoxin alone decreased the hemoglobin level. The inclusion of salinomycin (60 g per ton) in the diet with 2.5 or 5 mg per kg of aflatoxin initiated no significant change in body weight or feed efficiency. No significant interaction was observed between aflatoxin and salinomycin on any of the parameters measured.

Effect of iodine-treated water on the performance of broiler chickens reared under various stocking densities.

A total of 544 day-old sexed broiler chicks were used to investigate the effects of 2 ppm iodine-treated water on body weight and feed efficiency when the chicks were reared at 900, 720, 540, and 360-cm2 stocking densities. Chicks were fed a corn-soybean meal diet calculated to contain 3,212 kcal ME/kg and 21.58% CP. Iodine added to the drinking water at the rate of 2 ppm improved growth significantly after 4 wk of age. Feed efficiency was not significantly affected by the addition of iodine to the drinking water. Maximum effects on growth were obtained when the broilers were housed at stocking densities of 720 and 540 cm2/bird. A stocking density of 360 cm2 appeared to provide a crowding stress severe enough to negate the beneficial effects of adding iodine to the drinking water.