DAMAGES CAUSED BY MASTITIS IN SANTA INÊS BRAZILIAN SHEEP BREED

ABSTRACT In meat sheep herds in Brazil, mastitis has provoked many damages, causing mortality and decreasing the numbers of lambs born and weaned, posing heavy economic impacts for the production system. The objective of this study was to quantify the damages caused by mastitis in a Santa Inês breed herd, reared in a semi-intensive production system, in São Paulo State, Brazil. Clinical exams were conducted and the California mastitis test was carried out, and milk samples were taken from the ewes for microbiological assay. The lambs were weighed at birth and on the days when the milk samples were taken. Forty-one ewes gave birth to 55 lambs (birth rate of 1.34) during the parturition season from 23 October 2008 to 4 January 2009. Twenty (36%) of them died, 14 (70%) in the first 2 weeks following birth, and 6 (30%) before weaning, which occurs at about 70 days. A total of 70% (14) of the deaths were imputed to the occurrence of mastitis in the respective ewe, and 30% (6) to other causes, mainly pneumonia. Mastitis decreased the average daily gain of the lambs from birth to weaning (P < 0.10). Most of the positive microbiological samples (85.8%) where positive for Staphylococcus spp.