Variability of microbial teat skin flora in relation to farming practices and individual dairy cow characteristics

This study is the first that assessed the influence of farming practices and individual cow characteristics on a large number of microbial groups ( = 10) and cow samples ( = 192). Its aim was to establish how farming practices and intrinsic characteristics of dairy cows can influence the microbiota on teat skin. Microbial flora of 96 cow teat skin from 16 farms, sampled during milking and before washing, was counted on ten dairy-specific media. Gram-positive catalase-positive bacteria including coagulase-negative staphylococci, were at high level on teat skin (4.7 +/- 1.5 log cfu.mL(-1)) whereas lactobacilli, enterococci, Gram-negative bacteria, moulds and yeasts were at a level below 3 log cfu.mL(-1). Gram-positive catalase-positive bacteria and yeasts were lower in heifers and when milking hygiene practices were intensive. Higher and counts were linked to a silage-based diet, free stalls with straw bedding and moderate milking hygiene but also to multiparous cows. This study showed that dairy cow characteristics could interact with farming practices to affect the counts of microbial flora on teat skin. It offered prospects to better control teat microbial balance taking into account the milking hygiene practices, the parturition and the type of animal housing.