Biosecurity Practices to Limit Spread of Staphylococcus aureus on Ontario Sentinel Dairy Farms

Abstract

From May 1997 to December 1998, 40 dairy veterinarians from across the province, and 60 of their dairy producer clients, participated in the Sentinel Herd pilot project. Composite milk samples from all lactating cows in each herd were collected and cultured every 4 months. A milking and management questionnaire was administered to each participating producer at the time of the initial herd culture. Several questions pertaining to the herd's biosecurity practices were included. Based on the first 4 rounds of herd cultures, only 4 herds did not have any cows from which Staphylococcus aureus (HS) was isolated (negative herds). Three herds had positive cows on 1 herd culture and 6 herds had positive cows on 2 herds cultures. Fifteen herds were positive 3 times and 32 herds, all 4 times. As HS has been shown to be present in most of these herds, it is likely that many herds run a great risk of introducing this infection at some time. Therefore, it is of importance to examine the factors that appear to control it within a herd, once introduced.