Sokale AO, Williams CJ, Hoerr FJ, Collins KEC, Peebles ED. Effects of administration of an in ovo coccidiosis vaccine at different embryonic ages on vaccine cycling and performance of broiler chickens
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Poult Sci 2020;
100:100914. [PMID:
33518328 PMCID:
PMC7936202 DOI:
10.1016/j.psj.2020.11.078]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 11/11/2020] [Accepted: 11/23/2020] [Indexed: 11/29/2022] Open
Abstract
Use of a live coccidiosis vaccine has become an increasingly common method to control coccidiosis, especially in antibiotic-free broiler production. The Inovocox EM1 vaccine (EM1) is recommended for the vaccination of embryonated broiler hatching eggs between 18.0 and 19.0 d of incubation (doi). This allows for earlier acquisition of immunity to wild-type coccidia. However, it is unclear whether the difference in embryo age at the time of in ovo injection can influence the effect of the vaccine during grow-out as well as if the growth performance of broiler chickens is affected. Therefore, the objective of the study was to evaluate the effects of 2 injection ages (18.5 and 19.0 doi) and 3 injection types (noninjected, diluent, and vaccine) in a 3 × 2 factorial design, consisting of 10 replicates per treatment (60 treatment-replicate groups). There was a significant effect of injection age on BW at 0, 14, and 35 d after hatch, with a difference in the BW of birds belonging to the 18.5 and 19.0 doi groups up to day 35 after hatch. There was a significant effect of injection type on BW gain, feed intake, and FCR between 0 and 28 d after hatch. Between 0 and 35 d, FCR was lower in the vaccine-injected group in comparison with the noninjected and diluent control groups. Furthermore, total intestine coccidia and lesion indices were higher in the vaccine-18.5 treatment group in comparison with the diluent-18.5 treatment group at 28 d. In conclusion, hatchling weight was affected by injection age, and this subsequently affected growth performance. Furthermore, intestinal coccidia cycling peaked at 28 d, resulting in a reduction in growth performance through 28 d and subsequent compensatory growth by 35 d. There was no significant difference in coccidiosis cycling between the vaccine-18.5 and vaccine-19.0 doi treatment combination groups.
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