Longitudinal Study for the Detection and Quantification of spp. in Dairy Cows during Milking and in the Dairy Farm Environment.

Campylobacteriosis outbreaks have repeatedly been associated with the consumption of raw milk. This study aimed to explore the variation in the prevalence and concentration of spp. in cows' milk and feces, the farm environment and on the teat skin over an entire year at a small German dairy farm. Bi-weekly samples were collected from the environment (boot socks), teats, raw milk, milk filters, milking clusters and feces collected from the recta of dairy cows. Samples were analyzed for spp., , the total aerobic plate count and for spp. The prevalence of spp. was found to be the highest in feces (77.1%), completely absent in milking equipment and low in raw milk (0.4%). The mean concentration of spp. was 2.43 log colony-forming units (CFU)/g in feces and 1.26 log CFU/teat swab. Only a single milk filter at the end of the milk pipeline and one individual cow's raw milk sample were positive on the same day, with a concentration of 2.74 log CFU/filter and 2.37 log CFU/mL for the raw milk. On the same day, nine teat swab samples tested positive for spp. This study highlights the persistence of spp. for at least one year in the intestine of individual cows and within the general farm environment and demonstrates that fecal cross-contamination of the teats can occur even when the contamination of raw milk is a rare event.