Investigation of Factors Associated With Bovine Mastitis in a Compost Barn System and Identification of Microorganisms Involved, Using Maldi-Tof Mass Spectrometry

Objective: To investigate factors associated with bovine mastitis in a Compost Barn system and to use MALDI-TOF mass spectrometry to determine the microorganisms involved in the infection. Theoretical Reference: Mastitis negatively impacts dairy farming. To target control measures efficiently, it is important to assess predisposing factors and identify microorganisms. The MALDI-TOF MS technique can contribute to this. Method: Subclinical mastitis was diagnosed by the California Mastitis Test (CMT), with milk collected from positive teats for microbiological analysis by Gram staining and subsequent identification by MALDI-TOF mass spectrometry. Teats were classified for hyperkeratosis and dirt according to standardized methodologies. The seasonal influence on mastitis was analyzed based on local climate data. Results and Discussion: The prevalence of mastitis in the Compost Barn was 35%, with a higher frequency in the warmer, rainier months. There was an association between the occurrence of mastitis and hyperkeratosis (p<0.000001) and dirt (p = 0.02) in the Compost Barn system. Staphylococcus and Bacillus predominated in cases of mastitis. There was no dependence between the type of microorganism and the degree of subclinical mastitis (p = 0.053). Research implications: The results may contribute to developing efficient strategies to combat and control bovine mastitis in the dairy sector. Originality/value: This study contributes to the literature by showing the association of factors with the occurrence of bovine mastitis on dairy farms in the north of Minas Gerais. Using the MALDI-TOF MS technique, it also contributes to the libraries of microorganisms involved in cases of mastitis. The relevance and value of this research are evidenced by its influence on the decision-making process of dairy farmers.