Machine milking risk factors for teat end callosity in dairy cows on herd level

The objectives of this study were to evaluate the effect of milking on teat-end callosity (TEC) at herd Level. In total, 192 farms were visited once to collect data on the milking management, teat condition and milking machine function. Teat-end callosity was grouped into four categories: no callosity, smooth callosity, rough callosity, and very rough callosity. Teats in the rough and very rough callosity category were regarded as exhibiting a higher risk for clinical mastitis. Therefore, the percentage of teats within a herd with rough and very rough callosity (%ROUGH) was used as the dependent variable in a basic generalized linear model with a Logit [ink in which the effects of single independent variables were analysed. Farms with milking parlours using a milk meter had on average higher %ROUGH than farms with high mounted milk recorder jars or without milk measurement. Longer machine-on time resulted in higher %ROUGH. Higher vacuum differences in the short milk tube were associated with Lower %ROUGH as were increasing diameters of the short milk tube. At the same time feeding of concentrates in the milking parlour was associated with lower %ROUGH than individual feeding. There was an association between teat cup Liner brand and %ROUGH. More concave and flat teat-ends showed Lower %ROUGH. Post-milking teat disinfection was associated with higher %ROUGH compared to no post-milking teat disinfection. Increases in rough and very rough teat-end callosity are associated with increased incidence of clinical mastitis, and therefore teat-end callosity can be used as a monitoring tool for assessing the quality of milking, management and machine handling.