title: F strain Mycoplasma gallisepticum vaccination of post-production-peak commercial Leghorns and its effect on egg and eggshell quality.
abstract: Forty-five-week-old commercial leghorns negative for antibodies to Mycoplasma gallisepticum (MG) and M. synoviae were vaccinated with high-passage F strain MG (FMG). Hens were confined in modified Horsfall-Bauer isolation units through 60 weeks of age. Egg production (% hen day) and parameters of egg and eggshell quality were monitored, including egg weight, eggshell strength, Haugh unit score, pimpling, and blood/meat spot incidence. Egg production was significantly lower (P less than 0.05) for FMG vaccinates than controls (down 5.76% and 5.80% in Trials 1 and 2, respectively). However, vaccinates and controls did not differ significantly in eggshell strength, shell thickness, pimpling, or blood/meat spot incidence. Haugh unit scores were significantly (P less than 0.05) greater for FMG vaccinates. At necropsy, all reproductive tracts appeared grossly normal. These studies suggest that high-passage FMG vaccination of post-production-peak hens does not adversely affect oviduct function.
authors.affiliation: U.S. Department of Agriculture, ARS, South Central Poultry Research Laboratory, Mississippi State, Mississippi 39762.
authors.forename: S L
authors.initials: SL
authors.lastname: Branton
authors.forename: B D
authors.initials: BD
authors.lastname: Lott
authors.forename: J W
authors.initials: JW
authors.lastname: Deaton
authors.forename: J M
authors.initials: JM
authors.lastname: Hardin
authors.forename: W R
authors.initials: WR
authors.lastname: Maslin
mesh_terms: D000818:Animals; D001428:Bacterial Vaccines / Q000009:adverse effects*; D002645:Chickens / Q000276:immunology*; D004528:Egg Shell / Q000187:drug effects*; D004531:Eggs / Q000592:standards*; D005260:Female; D005836:Genitalia, Female / Q000473:pathology; D009174:Mycoplasma / Q000276:immunology*
chemical_list: D001428:Bacterial Vaccines