Milkability characteristics of Jersey cows throughout the lactation and their effect on milking induced teat prolongation

The aim of this study was to monitor milkability traits of Jersey cows over the course of lactation, and to investigate how milkability characteristics affected milking induced teat prolongation (MITP; %). For the purpose of the experiment, milkability parameters and teat length of 43 Jersey cows were monitored throughout the lactation. The effects of milk yield, milking time, lag time, average milk flow, and milk flow during various stages of milking on milking induced teat prolongation were evaluated. Jersey cows in this study achieved an average daily milk yield of 16.8 kg with an average milking time of 5 min. The average milk flow was 1.73 kg min-1 and the occurrence of bimodal milk flows was 23.8 %. Milkability characteristics significantly affected MITP. Milk yield, lag time and milk flow at the beginning of milking affected the MITP of both pairs of teats, while average milk flow and milk flow during the second minute of milking showed significant differences only for MITP of front teats. Furthermore, MITP was not dependent on milking time nor milk flow after the second min of milking, but was strongly affected by milk yield and milk flow disturbances at the beginning of milking. Higher MITP was observed for high milk yields, low lag times, normal milk flows at the beginning of milking, and fast milk flows during the milking. Thus, the desired milkability characteristics caused higher MITP. The findings of this study suggest that the high teat prolongation during milking might be interpreted as a positive sign for milking efficiency.