VACCINATION OF BROILERS WITH HVT EXPRESSING AN EIMERIA ACERVULINA ANTIGEN IMPROVES PERFORMANCE AFTER CHALLENGE WITH EIMERIA

The sequence encoding part of the 100 kDa refractile body protein (Ea1A) from Eimeria acervulina was cloned into the US10 locus of herpesvirus of turkeys (HVT) downstream of LTR promoter. Expression of the fusion protein was shown in vitro. Recombinant HVT showed a delayed and slightly reduced level of viremia compared to the parent strain in SPF chickens as well as in broilers. Effect on the performance of broilers vaccinated with recombinant or parent HVT was measured by challenge at day 24 with a high dose of E. acervulina and E. maxima oocysts. A significant improvement in weight of animals vaccinated with the recombinant HVT was detected at the end of the challenge period.