Egg quality in laying hens exposed to Mycoplasma gallisepticum F-strain attenuated vaccine

Abstract

Mycoplasma gallisepticum causes coughing, ocular and nasal discharge, reduction in feed intake, lower and uneven growth, decline in egg production and quality, and increase in mortality. Among the attenuated vaccination strains, MGF can reduce clinical signs and lesions in layer hens, stimulate immune responses of cellular and humoral basis, act as an instrument of competitive exclusion in relation to field strains, and reduce the use of antimicrobials. This study aimed to investigate the effects of attenuated MG F-strain vaccination on egg quality in 3 groups of 30 hens each, being one control and 2 vaccinated. Vaccination was applied by ocular route at 8 and 12 wk of age. Comparisons were made among unvaccinated hens; vaccinated at 8 wk of age; and vaccinated at 8 and 12 wk of age. There were no statistical differences in eggshell thickness and weight among groups. Eggs from twice vaccinated birds yielded a Haugh unit significantly lower than the other groups without affecting egg classification. There was no significant difference in ELISA results between the vaccinated groups.

Analysis of deep sequencing exosome‐microRNA expression profile derived from CP‐II reveals potential role of gga‐miRNA‐451 in inflammation

“…Mycoplasma gallisepticum (MG) is one of the most important avian pathogens. It is established that MG infection causes the chronic respiratory disease (CRD) leading to respiratory symptoms including rales, coughs, ocular discharge and nasal discharge in chickens and turkeys 1,2 . Increased embryonic mortality, reduced weight gain and egg production have been found in infected chickens, typically causing considerable economic losses to the poultry industry 3,4 …”

Down-regulated gga-miR-223 inhibits proliferation and induces apoptosis of MG-infected DF-1 cells by targeting FOXO3

“…Although vaccination and antibiotics can be used to control the infection, it is impossible to completely clear MG from infected chickens. MG-caused avian chronic respiratory disease has an increased epidemic, leading to tremendous economic losses in poultry industry [2]. MG-HS, isolated from a chicken farm in Hubei Province, was demonstrated to be a virulent strain of MG through a series of physiological and biochemical reactions [3].…”

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“…Among the isolated mycoplasmas from poultry, Mycoplasma gallisepticum (MG), M. synoviae (MS), M. meleagridis (MM) and M. iowae (MI) are the main pathogenic agents for chickens and turkeys [1,2] . MG infection causes significant economic losses in the poultry industry due to downgrading of carcasses at slaughter because of airsacculitis, treatment costs, and due to its effect on flocks performance [3,4] , and reduction of egg production in chickens, turkeys and other avian species were reported [5,6] . MG infection mainly is transmitted through ovaries, and the MG-infected breeder flocks should be depopulated; hence, the preferred method for MG control is to maintain MG-free flocks [7] .…”