Prevalence of pathogens associated with bovine mastitis in bulk tank milk in Mexico

Mastitis as cause of low milk production coupled with the use of medication to control it cause dairy farms to register large economic losses. Microorganisms' prevalence, and somatic cell counts (SCCs) were determined in 112 Holstein bovine herds in two bulk tank milk-screening assays. Detection of Staphylococcus aureus, Streptococcus agalactiae, and Mycoplasma spp. as microorganisms primarily responsible for clinical and subclinical mastitis and their relationship with SCCs was evaluated by Student's t-test and the kappa test. Prevalence of Mycoplasma was 55%; of S. aureus, 30%; of Streptococcus uberis, 37.5%; and of Staphylococcus coagulase-negative, 38.3%. The geometric mean of the SCC was 465,000 cells/mL. No significant differences were observed in the SCCs between the positive and negative samples of pathogens isolated (P > 0.5). There was a low kappa value of Mycoplasma correlation between samplings (kappa value = 0.10). This work aimed to understand the relationship between the prevalence of mastitis pathogens in bulk tank milk and SCCs in bovine herds in the central part of Mexico.