Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, Kungsängen Research Centre, Uppsala, Sweden.
J Dairy Sci. 2010 Mar;93(3):1069-73. doi: 10.3168/jds.2009-2419.
An accurate estimation of the daily milk yield of dairy cows milked in an automatic milking system is not obvious because of variations in milking intervals and frequencies. Daily harvested milk varies substantially, and developing a method to be used for estimating daily milk production is of great importance. Three calculation methods (simple, semiadvanced, and advanced) were used. The simple method calculated rough daily milk production by summing up the yield per day. The semiadvanced used yield in combination with time since last milking to calculate the milk production per hour between milking; an average of the milk production per hour over the day was calculated and multiplied by 24. The advanced method calculated the milk production from midnight to midnight by using information about yield and time since last milking to calculate the exact milk production. The results show a clear preference for the advanced calculation method because the variation [variation for the advanced method=ln(1.79) for first lactation and ln(2.28) for later lactations] between days was reduced significantly (3 to 4 times lower compared with the simple method). Variation in daily harvested milk can be used as a management tool.
由于挤奶间隔和频率的变化，自动挤奶系统中奶牛的日奶产量的准确估计并不明显。每日收获的牛奶量有很大差异，因此开发一种用于估计日产量的方法非常重要。使用了三种计算方法（简单、半先进和先进）。简单的方法通过每天的产量总和来粗略计算每日牛奶产量。半先进的方法结合上次挤奶时间来计算每小时的产奶量；计算一天中每小时产奶量的平均值，然后乘以 24。先进的方法通过使用有关产量和上次挤奶时间的信息，从午夜到午夜计算牛奶产量。结果表明，先进的计算方法明显更受欢迎，因为日变化（初产的先进方法的变化=ln(1.79)，后期产的变化=ln(2.28)）显著降低（与简单方法相比降低了 3 到 4 倍）。每日收获牛奶的变化可以作为一种管理工具。
