Relationship between individual-cow udder health status in early lactation and dairy cow characteristics in Brittany, France

Abstract

Data from a 4-year ecopathological survey involving 47 dairy farms in Brittany (France) were used to determine the individual animal characteristics associated with the udder health profiles of clinical and subclinical mastitis, and the presence of minor or major pathogens in milk during early lactation. Herd effect was taken into account and a within-herd analysis using factorial correspondence analysis and a decomposition of chi-square distance was performed. In primiparous cows, the main association observed was between milk production and intramammary infections with major pathogens. The dirtiness score showed contradictory relationships with udder health profiles. The indoor/outdoor transition period was unfavourable for udder health status; since the frequency rate of subclinical and clinical mastitis increased during this period. In multiparous cows, intramammary infections by minor or major pathogens were closely associated with non-infectious udder diseases, but the main effect was due to parity. Old cows were generally affected by higher somatic cell counts than younger cows regardless of whether the SCC were associated with clinical mastitis or not.