Effects of coccidiosis vaccination administered by in ovo injection on Ross 708 broiler performance through 14 days of post-hatch age
Effects of the in ovo injection of a commercial coccidiosis vaccine on various hatching chick quality variables and 14 d post-hatch (dph) oocyst shedding have been previously examined. The current study was designed to examine the performance of Ross 708 broilers during the 14 dph period of oocyst shedding following the application of the coccidiosis vaccine. On each of 7 replicate tray levels of a single-stage incubator, a total of 4 treatment groups was randomly represented, with each treatment group containing 63 eggs. Treatments were administered using a commercial multi-egg injector on d 18.5 of incubation. The treatments included 3 control groups (non-injected, dry-punch, and diluent-injected) and one treatment group (injected with diluent containing Inovocox EM1 vaccine). On d 21 of incubation, 20 chicks from each of the 28 treatment-replicate groups were placed in corresponding wire-floored battery cages. Mortality, feed intake (FI), BW gain (BWG), and feed conversion ratio (FCR) were determined for the zero to 7, 7 to 14, and cumulative zero to 14 dph intervals. There were no significant treatment effects on mortality in any interval or on BW at zero dph. There were significant treatment effects on BW at 7 and 14 dph, on BWG and FI in the zero to 7, 7 to 14, and zero to 14 dph intervals, and on FCR in the 7 to 14 and zero to 14 dph intervals. Although the performance variables of birds belonging to the diluent-injected and vaccine-injected groups were not significantly different, the 14 dph BW, 7 to 14 dph FI, and zero to 14 dph BWG and FI of birds belonging to the vaccine treatment group were significantly higher than those in birds belonging to the non-injected control group. It was concluded that use of the Inovocox EM1 vaccine in commercial diluent has no detrimental effect on the overall post-hatch performance of broilers through 14 dph.