PREVALENCE AND ETIOLOGY OF SUBCLINIC BOVINE MASTITES IN DAIRY PROPERTIES WITH MECHANICAL MILKING PROCESS IN THE STATE OF GOIÁS

Abstract

Samples from 942 cows were tested by the California Mastitis Test – CMT. Most of them were black and white holstein, apparently healthy animals, from 25 dairy farms, located in the State of Goiás, in which milking process was made mechanically. It was found that 375 (39.8%) animals showed positive results to CMT in values ranging from +, ++, +++. Milk from each CMT reactive teat, 667 samples in total, was bacteriologically analised in an attempt to isolate and identify microorganisms associated with intramammarian infections, obtaining 938 strains in pure culture or in association, as follows: Staphylococcus aureus, 291 times (30.2%); Corynebacterium bovis, 120 times (12.5%); coagulase negative Staphylococcus, 112 times (11.6%); Streptococcus agalactiae, 14 times (1.5%); Streptococcus uberis, 36 times (3.7%); Streptococcus pyogenes, 12 times (1.2%); Streptococcus spp, 66 times (6.9%); Pseudomonas spp., 96 times (10.0%); Corynebacterium pyogenes, 24 times (2.5%); Escherichia coli, 60 times (6.2%); Nocardia spp.p. 14 times (1.5%) and others, 93 times (9.6%). These microorganisms were considered as being either primarily pathogens (55.8%) or contaminants (41.6%).

KEY-WORDS: Subclinical mastitis; primarily pathogens; contaminant pathogens.