Relationship between mastitis prevalence and farm management practices for mountain dairy farms in the western Alps

Logistic limitations in mountain areas make hard to assure assistance and veterinary services for dairy farms, inducing a high incidence of mastitis. Here, the way to improve herd’s health is prevention. Our study aimed at identifying the relationship between mastitis prevalence and farm management practices for mountain dairy farms in the western Alps. We selected 8 dairy farms of Lanzo’s Valleys differing for their farming practices. Each farm was visited before transhumance period (T0), 3 to 5 days after transhumance (T1) and approximately 1 month later (T2). At each visit, individual milk samples were collected for somatic cell count (SCC) and microbiological analysis to investigate the presence of contagious pathogens (CoP). Individual cow mammary gland, animal and bedding cleanness were evaluated through a score range between 1 (insufficient) and 3 (optimal). During visits, we surveyed data on animal characteristics, herd and farm management. The prevalence of CoP was then calculated at a herd level. A principal component (PC) analysis was run on microbiological data and SCC and cleanness scores, using farm management practices as non-active descriptive variables. The PC 1 was positively related to cleanness scores. Among descriptive non active variables PC1 was positively correlated to variables related to intensification level of the farms (milk yield, stocking rate, dietary concentrates, dairy cows/workforce unit, low crossbreed proposition). The PC2 was positively related to the prevalence of the CoP and milk SCC. Among non-active variables, PC2 was positively related to extensification level of the farm (altitude, grazing time/day, dietary pasture proportion, grazing season duration, age at first calving, lameness prevalence, lactation rank), suggesting that specialisation on dairy production better focus farmers attention on mammary health. The prevalence of CoP and SCC increased after transhumance, especially in T2, suggesting that the lack of veterinary assistance prevents farmers to monitor and control mastitis on upland