Incidence of contamination in the process of getting milk and susceptibility to antimicrobial

Abstract

The milking is a fundamental step for getting quality milk products, and factors related to the hygiene of the animal teats and of the milking equipment can take to contamination of the milk, raising this product’s bacterian count. Experiments were carried to evaluate the efficiency of the predipping on teats bacterian contamination reduction and on bacterian count of milk from cows that have been submitted to different conditions of preparation for the milking, and the susceptibility to antimicrobials profile of milk bacteria. On the experiment that tested the efficiency of the predipping there was significant difference as to the number of teats with Staphylococcus sp and also positive Gram bacilli between treatments with no sanitation or with water sanitation and predipping. As to the milk bacterian count of the mammary quarters, there was significant difference between the treatments without sanitation and pre-dipping. As to the bacterian susceptibility to antimicrobials, it showed resistance to five, from the eight that were tested, in at least one sample, being them: amoxilicin+clavulanic acid, enrofloxacin, gentamicin, G penicillin and vancomycin. The results allowed to conclude that: the predipping represents and important tool to reduce contamination on teats, as well as on milk; the presence of coagulase-negative Staphylococcus sp resistant to certain antimicrobials, like vancomycin, wasn’t expected, being a relevant observation from the milk quality point of view.