Assessment of beta-glucuronidase levels in goat's milk as an indicator of mastitis: comparison with other mastitis detection methods.

The use of somatic cell counts (SCCs) for the diagnosis of mastitis is not a well-established procedure for the caprine species, because nonleucocytic cell-like particles are normally observed as a result of the apocrine secretion process of the goat mammary gland. The infection levels of 124 goats were measured by the beta-glucuronidase test, which was compared with the SCC method and the California mastitis test (CMT). Seventy-nine of 124 samples (63.7%) showed SCCs lower than 1.3 x 10(3) cells per ml. Of these samples, 93% showed low levels of beta-glucuronidase activity (< 15 U/ml). In the remaining 36.3% of the samples, SCCs were higher than 1.3 x 10(3) cells per ml. Of these samples, 88% showed high levels of beta-glucuronidase activity (15 to 100 U/ml). The CMT gave similar results. In this study, the beta-glucuronidase test was standardized for goat milk and shown to be reliable, enabling one to count only the somatic enzyme cells in milk and avoiding the interference encountered with the SCC method.