Principales géneros bacterianos aislados de leche de cabra en dos granjas del municipio de Tequisquiapan, Querétaro, México Most frequent bacteria isolated from goats milk in two farms located in Tequisquiapan, Querétaro, México

The inflammation of the udder is known as mastitis and despite the economic impact that it causes in goats, very scarce information exist about this problem in Mexico. The aim of this study was to identify bacteria in raw milk from clinically healthy goats in intensive and semi-intensive production systems, through traditional microbiological methods. Twenty eight (28) animals from intensive production system and 33 animals from a semi-intensive production system were sampled from the Centro de Ensenanza Investigacion y Extension en Produccion Animal en Altiplano (CEIEPAAFMVZ-UNAM) and Granja del Carmen both located in Tequisquiapan, Queretaro, Mexico. The samples were obtained from both glands of each goat. The sampling was made to the selected goats every 45 d along the California mastitis test until 240 lactation days. A total of 484 samples were obtained for the traditional bacteriological analysis, 90 samples (18.60 %) were positive to bacterial growth of which 97 isolates were recovered. The most frequently bacteria isolated were coagulase-negative Staphylococcus (SCN) 62/97 (63.92 %), Streptococcus uberis 10/97 (10.31 %) and Staphylococcus aureus 5/97 (5.15 %). According to the statistical analysis, there are no differences between the two main bacterial genus isolated in intensive and semi-intensive production systems.