The Effect of Feeding Yolk Antibody to Phospholiapase a 2 (apla 2 ) on Growth and Feed Conversion in Broiler Chicks

s of papers 29 118 Effects of dietary ingredients and Eimeria acervulina infection of chick performance, MEn and amino acid digestibility. M. E. Persia*, P. L. Utterback, E. L. Young, and C. M. Parsons, University of Illinois. In each of four two-wk experiments, chicks were inoculated either on D 9 or 11 with 5.0 x 105 sporulated oocysts (acute infection) or D 9, 12, 15 and 18 with lower levels (5.0 x 104 to 1.5 x 105) of sporulated oocysts (chronic infection). In Experiment 1, crossbred chicks (New Hampshire x Columbian) were fed either normal or a pharmacologic level of Zn (1500 mg/kg) and were inoculated with various chronic levels of sporulated oocysts. The Zn had no effect and coccidiosis infection resulted in significant decreases in growth performance and MEn, but not amino acid digestibility. In Experiment 2, both fishmeal (15%) and GroBiotic-B70TM (GB; 5%) diets completely ameliorated the negative effects of acute and chronic coccidiosis infection on growth performance of crossbred chicks. The acute coccidiosis infection greatly reduced MEn and amino acid digestibility, and the magnitude of response varied with the timing of excreta collection after inoculation. Both fishmeal and GB diets reduced the large negative effects of coccidiosis infection on MEn and amino acid digestibility. Experiment 3 evaluated the effects of coccidiosis infection in chicks fed a wheat/barley/pectin diet compared to a corn/soybean meal diet. The wheat/barley/pectin diet depressed chick weight gain but did not interact with coccidiosis infection. Commercial broiler chicks were used in Experiment 4 to evaluate the effects of various levels of GB (2 to 6%) on growth performance of coccidiosis-infected chicks. Diets containing GB did not improve the growth performance of the infected broiler chicks, but they did improve the growth of the non-infected chicks. The results of these experiments indicate that coccidiosis infection (E. acervulina) reduces MEn and amino acid digestibility in chicks and that the coccidiosis effect is influenced by diet composition, type of infection (acute v. chronic) and timing of excreta collection.