Longitudinal Response of Commercial Broiler Operations to Bio-shuttle Administration

摘要

Coccidia have typically been controlled using anticoccidial drugs, while the use of vaccines has increased due to concerns over the development of drug resistance in Eimeria spp. Because they contain drug-sensitive Eimeria, vaccination has received interest as a potential intervention for managing drug resistance. Vaccines can also be used in conjunction with anticoccidial drugs as part of a bio-shuttle program in which vaccination of broilers on day of hatch is followed by the administration of an ionophore in-feed starting at approximately 16 to 18 d post-hatch. Although they have been demonstrated to mitigate Eimeria vaccine-related performance losses, very little research on the effects of bio-shuttle programs on growth performance, pathology, and Eimeria populations has been published. In this study, we developed a longitudinal profile of the response of commercial broiler chickens before, during, and after bio-shuttle application as part of the broader drug and vaccine program of a commercial integrator over a 12-month period. Evaluation of production data collected from a commercial integrator found that, overall, growth performance and intestinal Eimeria pathology to be worst during the bio-shuttle administration period and best during the period after bio-shuttle administration. The correspondence between growth performance and pathology suggests that the development of drug-resistant Eimeria populations may have been reduced or delayed by bio-shuttle application. The results of our study are expected to inform future research evaluating the effects of bio-shuttle administration in poultry production.