Mastitis in Holstein cows and associated factors in dairy farms in Córdoba, Argentina

Abstract

The objective of this study was to estimate the incidence of clinical mastitis (CM) in dairy farms and identify individual factors associated with these new episodes. Nine semipastoral dairy farms applying mastitis control and prevention measures were included and visited twice with an interval of 15 days. A random sample of cows was selected in the first visit and monitored during the following 15 days for the identification of new cases of CM. The incidence was determined as the ratio between the number of new CM cases during the follow-up period and the number of healthy cows at the first visit. The risk factors evaluated at cow level were udder hygiene, distance to the floor of the anterior quarter teat, parity and days in milk; at quarter level was evaluated the leaking milk, teat skin condition, presence of ring and hyperkeratosis and subclinical mastitis using the California Mastitis Test (CMT). A generalized mixed linear model was adjusted to evaluate the association between the factors surveyed and a new CM case. A total of 990 cows were analyzed and 62 (6.7%, 95% CI 5.0- 8.3) new cases of CM were identified. The factors associated to a new case of clinical mastitis in the final model were days in milking, udder hygiene and CMT level. Cows with very dirty udders (level 4) and CMT result ≥2 in at least one quarter showed odds ratio (OR) values of 2.56 (1.19-5.5) and 3.29 (1.5-7.2), respectively. Cow attributes identified as associated may be risk indicators for specific mammary health management in the dairy herd.