EFFECTS OF INITIAL LITTER CONTAMINATION LEVEL WITH EIMERIA-ACERVULINAON POPULATION-DYNAMICS AND PRODUCTION CHARACTERISTICS IN BROILERS

The present experiment was done to obtain experimental evidence suppor ting the existence of an optimal initial contamination level of Eimeri a acervulina with respect to broiler productivity, as suggested by sim ulation model outcomes. Three levels of initial (on Day 3) contaminati on of the litter were applied (low, intermediate and high). The peak o f oocyst excretion during the flock cycle (grow-out) (Days 0-36) depen ded on the initial contamination level. Oocysts peaked at Day 15, 22 a nd 33 for the high, intermediate and low contamination level, respecti vely. Antibody tit es and plasma carotenoid contents were not signific antly affected by contamination levels. Average body weight at the end of the flock cycle (Day 36) and average daily body weight gain were s ignificantly higher at the intermediate contamination level compared w ith the low and high contamination levels. Average body weight at Day 36 was 1681 g, 1712 g and 1674 g for the low, intermediate and high co ntamination level, respectively. Average daily weight gain was 45.7 g, 46.5 g and 45.5 g for the low, intermediate and high contamination le vel, respectively. Thus, the data from this experiment support the exi stence of an optimum initial contamination level for E. acervulina wit h respect to performance results.