Prevalence and effect of intramammary infection due to coagulasenegative staphylococcal (CNS) species in somatic cell counts in milk from Holstein dairy cows in Boyacá, Colombia.

Mastitis is one of the most important illnesses in specialized dairy herds worldwide due to the effects on production and animal health. The types caused by CNS has a special importance in a production where the main pathogens are controlled. The objective of the present work is to determine the prevalence of CNS in a dairy herd in Boyacá and also quantify the effects of every species of CNS in SCC. 40 cows were selected and sampled during 6 months, CMT was performed, and results from 1 to trace were sampled. The routine bacteriological test was also performed for CNS identification, and the isolating of CNS was performed through rpoB gene identification and through the type of strain using the pulse gel electrophoresis procedure. Out of 960 samples, 619 were positive for CNS growth. The most prevalent species were Staphylococcus epidermidis, S. chromogenes, S. sciuri, S. simulans, S. haemolyticus and S. capitis. The results that were found here are similar to the results observed in different parts of the world, which confirms that they are pathogens that must be constantly evaluated because they can go unnoticed in routine controls, especially in those farms where major pathogens are not a serious problem. The results determined in this study demonstrate that CNS generates a slight increase in somatic cells.