Broiler performance and intestinal alterations when fed drug-free diets.

A study was carried out to investigate the effects of a drug-free feeding program on broiler performance and intestinal morphology. Chicks vaccinated against coccidia were randomly assigned to 4 dietary treatments: 1) negative control (NC), basal diet; 2) positive control (PC), diet 1 + Lincomycin; 3) program 1 (PG1); diet 1 + Bio-Mos, Vegpro, MTB-100, Acid Pak 4-Way, and All-Lac XCL; 4) and program 2 (PG2), diet 1 + Bio-Mos and All-Lac XCL, each of which were assigned to 13 pens (48 birds in each of 52 pens). Growth traits (BW, feed intake, yield, mortality, BW gain, and feed conversion rate) were obtained through 49 d. At d 14, 3 chicks per pen were challenged with coccidia. Segments of duodenum, ileum, and ceca were removed to measure intestinal morphology at d 14, 28, 35, and 49. Final BW gain of broilers on PC (2.736 kg) was numerically higher than those for NC (2.650 kg). Cumulative feed conversion rate at d 49 was improved (P < 0.05) in birds consuming PC and PG2 compared with NC. Overall, mortality was higher for birds consuming the NC (P < 0.05) than the PC, PG1, and PG2 diets. Interaction of dietary treatments with age and age alone were evident (P < 0.0001) for morphology of duodenum, ileum, and ceca. Lamina propria in ceca was thicker (P < 0.008) in broilers consuming the NC than PG1 and PG2 diets. The results of this study indicated that feeding birds without growth promoters resulted in higher mortality and decreased growth performance than did feeding a diet with an antibiotic, and the combination of Bio-Mos and All-Lac XCL helped to reduce negative effects.

Effect of poultry diet on phosphorus in runoff from soils amended with poultry manure and compost.

Phosphorus in runoff from fields where poultry litter is surface-applied is an environmental concern. We investigated the effect of adding phytase and reducing supplemental P in poultry diets and composting poultry manures, with and without Fe and Al amendments, on P in manures, composts, and runoff. We used four diets: normal (no phytase) with 0.4% supplemental P, normal + phytase, phytase + 0.3% P, and phytase + 0.2% P. Adding phytase and decreasing supplemental P in diets reduced total P but increased water-extractable P in manure. Compared with manures, composting reduced both total P, due to dilution of manure with woodchips and straw, and water-extractable P, but beyond a dilution effect so that the ratio of water-extractable P to total P was less in compost than manure. Adding Fe and Al during composting did not consistently change total P or water-extractable P. Manures and composts were surface-applied to soil boxes at a rate of 50 kg total P ha(-1) and subjected to simulated rainfall, with runoff collected for 30 min. For manures, phytase and decreased P in diets had no significant effect on total P or molybdate-reactive P loads (kg ha(-1)) in runoff. Composting reduced total P and molybdate-reactive P loads in runoff, and adding Fe and Al to compost reduced total P but not molybdate-reactive P loads in runoff. Molybdate-reactive P in runoff (mg box(-1)) was well correlated to water-extractable P applied to boxes (mg box(-1)) in manures and composts. Therefore, the final environmental impact of dietary phytase will depend on the management of poultry diets, manure, and farm-scale P balances.

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.

Effects of feeding blends of grains naturally contaminated with Fusarium mycotoxins on production and metabolism in broilers.

Three hundred sixty, 1-d-old male broiler chicks were fed diets containing grains naturally contaminated with Fusarium mycotoxins for 56 d. The four diets included control (0.14 mg/kg deoxynivalenol, 18 mg/ kg fusaric acid, < 0.1 mg/kg zearalenone), low level of contaminated grains (4.7 mg/kg deoxynivalenol, 20.6 mg/kg fusaric acid, 0.2 mg/kg zearalenone), and high level of contaminated grains without (8.2 mg/kg deoxynivalenol, 20.3 mg/kg fusaric acid, 0.56 mg/kg zearalenone) and with (9.7 mg/kg deoxynivalenol, 21.6 mg/kg fusaric acid, 0.8 mg/kg zearalenone) 0.2% esterified-glucomannan polymer derived from Saccharomyces cerevisiae1026 (E-GM). Body weight gain and feed consumption responded in a significant quadratic fashion to the inclusion of contaminated grains during the finisher period. Efficiency of feed utilization, however, was not affected by diets. The feeding of contaminated grains in the finisher period also caused significant linear increases in blood erythrocyte count and serum uric acid concentration and a significant linear decline in the serum lipase activity. Dietary inclusion of contaminated grains resulted in a significant quadratic effect on serum albumin and y-glutamyltransferase activity. Blood hemoglobin and biliary IgA concentrations, however, responded in significant linear and quadratic fashions. Supplementation of E-GM counteracted most of the blood parameter alterations caused by the Fusarium mycotoxin-contaminated grains and reduced breast muscle redness. It was concluded that broiler chickens may be susceptible to Fusarium mycotoxicoses when naturally contaminated grains are fed containing a combination of mycotoxins.