Effects of simulated quarter and udder teat cup removal settings on strip milk and milking duration in dairy cows

摘要

The aim of this study was to estimate the amountof milk left in quarters and udders and the milkingduration for a variety of teat cup removal strategies. Acombination of empirical data and simulated quarterand udder teat cup removal settings were used to makethese estimates. Milking duration is an important factorin both automatic and conventional milking systems becauseit directly influences milking efficiency and hencecan affect farm profitability. Strategies investigated inthe literature to reduce milking duration include theapplication of different milk flow rate switch-points(milk flow rate at which the milking unit or teat cup isremoved). Applying these milk flow rate switch-pointscan affect the amount of milk that is not harvested(strip milk). We are not aware of previous researchanalyzing strip milk yield and milking duration at thequarter level, across a range of quarter and udder milkflow rate switch-points. Quarter-level average milkingduration decreased by 2 min, and strip milk increased1.3 kg as quarter milk flow rate switch-point was increasedfrom 0.2 kg/min to 1.0 kg/min. Using an endof milking criterion of removal of the teat cup at 50%of the quarter’s rolling average milk flow rate resultedin a 0.4-min reduction in milking duration and a 0.08-kg increase in strip milk per quarter, compared withremoval of the teat cup at 30% of the quarter’s rollingaverage milk flow rate. Udder-level average milkingduration decreased by 1.4 min, and strip milk increasedby 0.76 kg (0.19 kg per quarter) as udder milk flow rateswitch-point was increased from 0.2 kg/min to 1.0 kg/min. A 0.8-min reduction in cow milking duration anda 0.27-kg increase in strip milk at the udder level (0.08kg per quarter) resulted when changing udder milk flowrate switch-point from 30% of the udder rolling averageto 50% of the udder rolling average milk flow rate. Thisstudy provides quantitative estimates of the effect ofteat cup milk flow rate switch-points on milking durationand strip milk yield.