Influences of F-strainMycoplasma gallisepticum vaccine on productive and reproductive performance of commercial parent broiler chicken breeders on a multi-age farm

Abstract

The influences of F-strain Mycoplasma gallisepticum (FMG) vaccine inoculation during the pullet period on the subsequent productive and reproductive performance of parent broiler chicken breeders on a multi-age farm were evaluated. Three thousand breeders were randomly divided into 2 treatment groups that were either vaccinated with FMG (FMG-vaccinated group) or not vaccinated with FMG (FMG-free group). Body weight and egg production were determined through approximately 50 wk of age. Egg weight and feed conversion was determined at 26, 32, 35, 38, and 43 wk of age. Egg quality parameters, including eggshell strength, egg-specific gravity, egg shape index, blood-meat spots, Haugh unit score, eggshell thickness, yolk:albumen ratio, percentage yolk, albumen and eggshell weights, and percentage fertility, hatchability, and second-quality chicks were determined at 26, 32, and 43 wk of age. Air sacs were examined and lesions were scored at 20, 32, and 50 wk of age. The number of mature ovarian follicles, histologies of ovary, and lengths, and histologies of the infundibulum, magnum, isthmus, uterus, and vagina were determined. In the present study, an increase in egg production of broiler breeder hens in the FMG-vaccinated group during peak of lay was compared with the FMG-free group. Feed conversion of hens in the FMG-vaccinated group was significantly less at 32, 35, 38, and 43 wk of age. Eggs from hens in the FMG-vaccinated group had a significantly higher Haugh units score at 26 wk of age and had a significantly higher eggshell thickness and lower incidence of blood-meat spots at 32 wk. Hatching eggs from hens in the FMG-vaccinated group had a significantly higher hatchability. The mean lesion score of air-sac lesion of birds in the FMG-vaccinated group was significantly less than FMG-vaccinated group. Uteruses of hens in the FMG-vaccinated group had a significantly longer length compared with the FMG-free group at 32 wk of age. The results indicate that inoculation of commercial parent broiler chicken breeders with the FMG vaccine before laying may prevent infection by field M. gallisepticum, and facilitate productive and reproductive performance.