COMPARISON OF PERFORMANCE OF ROSS BROILER BREEDER MALES TO FULL, HALF-DOSE AND 10X DOSE OF COCCIVAC®-D DAY-OF-AGE VACCINATION

S.W. Davis1, R.A. Phillips2 and C. Broussard2
1Colorado Quality Research, Wellington, Colorado, USA
steve@coloradoqualityresearch.com
2Schering-Plough Animal Health, Union, New Jersey, USA

Coccivac®-D is commonly administered to commercial broiler breeder replacement pullet and cockerel flocks at a half-dose of the manufacturer’s recommended dosage in the theory that the lower dosage results in improved flock livability and uniformity compared to full dose administration. This commercial practice of using the half-dose of Coccivac®-D is most prevalent in flocks of Ross broiler breeder males. The objective of this study was to determine if there are differences in the Ross 344 male broiler breeder in its response to varying doses of Coccivac-D day-of-age vaccination. Environmental conditions including floor, feeder and water space, temperature, lighting, vaccination and feeding programs were designed to replicate typical commercial broiler breeder production in the USA industry. Treatments were compared by 21 day gross coccidiosis scores, 28 and 70 day body weights, uniformity and feed conversion and 70 day livability results. The 21 day gross coccidiosis lesion scores resulted in significantly (P>.05) lower scores in the 10X dose treatment compared to the half-dose plus Amprol treatment. Body weights and the individual bird weight uniformity results were similar and showed no differences between treatments at 28 and 70 days. There was also no significant difference between treatments in 70 day livability results. This study concluded that there were no measurable performance improvements gained by administering a half-dose of Coccivac®-D to Ross 344 broiler breeder males compared to the manufacturer’s recommended dosage. The investigation shows that multiple doses (10X) of the vaccine resulted in less 21 day coccidiosis lesions compared to the half-dose application. These results may indicate that the lower dosage practice may inhibit rapid and uniform flock coccidiosis immunity that could lead to rolling reactions and delayed flock immunity.