Influence of dirtiness and hyperkeratosis teat in occurrence of bovine subclinical mastitis

Résumé

The influence of dirtiness and hyperkeratosis teat in the occurrence of subclinical mastitis was evaluated in cattle of Oliveira (MG) with 70 dairy cows in the summer and 77 in winter, 2012. The teats were classified through the hyperkeratosis degree and dirtiness level according to methods described in the literature. The detection of animals with mastitis was performed by California Mastitis Test. The prevalence teats with mastitis, hyperkeratosis and dirty were 37.6, 87.9 and 71.4% in summer, respectively. In winter, the prevalences were 39.6, 73.2 and 68.8%, respectively. Teats with hyperkeratosis have 8.3 times the risk of having mastitis that healthy teats (p<0.05). The dirtiness no affected (p>0.05) the occurrence of subclinical mastitis. The maintenance of milking machine should be performed in cattle with a high prevalence of hyperkeratosis teat. The sources of dirt on cows teats should be detected in free-stall system.