Risk factor for repeated cases of clinical mastitis in high-producing dairy cows

Author(s)

Arthur Pombo Almeida

• Document type: Master's Dissertation
• Press: Botucatu. 2016-02-26.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Medicina Veterinária e Zootecnia. Botucatu
• Defense date: 2016-02-15
• Advisor: José Carlos de Figueiredo Pantoja

Abstract

The objective of this study was to identify risk factors for the occurrence of repeated cases of clinical mastitis (CM). Two farms were visited monthly during 10 months. Milk samples were collected from all cases of CM. Cows were observed prospectively and a case was defined when a cow experienced the second case of CM within the same lactation. For each repeated case, three controls matched by days in milk (DIM) were randomly selected from the cohort of cows who did not experience CM. On each visit day, a series of udder and teat characteristics were recorded during milking. The median time to occurrence of the first case of CM was 84 DIM and the median interval between the first and second cases was 39 days. Teat to ground distance, teat-end hyperkeratosis, and milk production were individually associated with the occurrence of a repeated case of CM but did not remain in the final multivariable model. The odds of a repeated case of CM were 3.7 times greater for cows who were “very easy to milk”, as compared to cows who were “difficult to milk”. Cows who had their udders below the hock, and those of parity > 2 were 3.6 and 2.5 times more likely to experience a repeated case of CM, as compared to cows whose udder was positioned above the hock, and cows of parity 1, respectively. Findings of this study highlight the importance of teat and udder characteristics as risk factors for repeated cases of CM. (AU)

• FAPESP's process: 14/12642-0 - Udder and teat characteristics associated with repeated cases of clinical mastitis in high producing dairy cows
• Grantee: Arthur Pombo Almeida
• Support Opportunities: Scholarships in Brazil - Master