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

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.

Mastitis outbreak due to Mycoplasma californicum and Mycoplasma canadense in a commercial dairy herd in the state of Jalisco, México.

A commercial dairy herd with 282 cows in lactation suddenly began to have a problem with atypical clinical mastitis. The first 28 cases showed severe purulent mastitis with hard swollen mammary glands, but without systemic signs of illness Some of the cows were lame. The cases were not responsive to antibiotics. The evidence suggested that milking machine malfunction and other management practices may have contributed to spread infection and to increase the number of clinical cases. Culture of milk of the affected cows and bulk tank milk yielded mycoplasma colonies that were identified as Mycoplasma californicum and Mycoplasma canadense. This is the first isolation and report of these mycoplasmas in México and Latin America. The 28 positive cows were segregated and culled; however, the owner did not follow the recommendations to sample all the milking and dry cows and to implement other preventive measures. Consequently, losses were much greater and 177 cows were culled.