1Animal & Grassland Research and Innovation Centre,Teagasc,Moorepark,Fermoy,Co. Cork,Ireland.
2Department of Biological Sciences,Cork Institute of Technology,Bishopstown,Co. Cork,Ireland.
Animal. 2018 Apr;12(4):853-863. doi: 10.1017/S1751731117002221. Epub 2017 Sep 21.
The objective of this experiment was to establish the effect of low-concentrate (LC) and high-concentrate (HC) supplementation in the early and late periods of lactation on milk production and cow traffic in a pasture-based automatic milking (AM) system. In total, 40 cows (10 primiparous and 30 multiparous) were randomly assigned to one of the two treatments. The experimental periods for the early and late lactation trials extended from 23 February to 12 April 2015 and 31 August to 18 October 2015, respectively (49 days in each trial period). The early lactation supplement levels were 2.3 and 4.4 kg/cow per day for LC and HC, respectively, whereas the late lactation supplement levels were 0.5 and 2.7 kg/cow per day for LC and HC, respectively. Variables measured included milking frequency, milking interval, milking outcome and milking characteristics, milk yield/visit and per day, wait time/visit and per day, return time/visit and the distribution of gate passes. As the herd was seasonal (spring) calving, the experimental periods could not run concurrently and as a result no statistical comparison between the periods was conducted. There was no significant effect of treatment in the early lactation period on any of the milk production, milking characteristics or cow traffic variables. However, treatment did significantly affect the distribution of gate passes, with the HC cows recording significantly more gate passes in the hours preceding the gate time change such as hours 7 (P<0.01), 15 (P<0.05), 20, 21 (P<0.001), and 22 (P<0.05), whereas the LC treatment recorded significantly more gate passes in the hours succeeding the gate time change, such as time points 2 (P<0.01) and 10 (P<0.05). There was a significant effect of treatment in late lactation, with HC having a greater milk yield (P<0.01), milking duration and activity/day (P<0.05), while also having a significantly shorter milking interval (P<0.05) and return time/visit (P<0.01). The distribution of gate passes were similar to the early lactation period, with HC also recording a significantly greater number of gate passes during the early morning period (P<0.01) when visitations were at their lowest. Any decision regarding the supplementing of dairy cows with concentrates needs to be examined from an economic perspective, to establish if the milk production and cow traffic benefits displayed in late lactation outweigh the cost of the concentrate; thereby ensuring that the decision to supplement is financially prudent.
本实验旨在确定泌乳早期和晚期低浓度（LC）和高浓度（HC）补充对牧场自动挤奶（AM）系统产奶量和奶牛流量的影响。共有 40 头奶牛（10 头初产奶牛和 30 头经产奶牛）被随机分配到两种处理方法之一。早期和晚期泌乳试验的实验期分别从 2015 年 2 月 23 日持续到 4 月 12 日和 2015 年 8 月 31 日持续到 10 月 18 日（每个试验期 49 天）。早期泌乳的补充水平分别为 LC 和 HC 每头奶牛每天 2.3 和 4.4 公斤，而晚期泌乳的补充水平分别为 LC 和 HC 每头奶牛每天 0.5 和 2.7 公斤。测量的变量包括挤奶频率、挤奶间隔、挤奶结果和挤奶特征、产奶量/次和每天、等待时间/次和每天、返回时间/次和门卡分布。由于牛群是季节性（春季）产犊，因此实验期不能同时进行，因此没有对两个时期进行统计比较。在早期泌乳期，处理方法对任何产奶量、挤奶特征或奶牛流量变量都没有显著影响。然而，处理方法确实显著影响了门卡的分布，HC 奶牛在门时间变化前的几个小时内记录的门卡明显更多，例如 7 小时（P<0.01）、15 小时（P<0.05）、20 小时、21 小时（P<0.001）和 22 小时（P<0.05），而 LC 处理方法在门时间变化后几个小时内记录的门卡明显更多，例如 2 小时（P<0.01）和 10 小时（P<0.05）。在晚期泌乳时，处理方法有显著的效果，HC 的产奶量更大（P<0.01），挤奶时间和活动量/天（P<0.05），同时挤奶间隔更短（P<0.05）和返回时间/次（P<0.01）。门卡的分布与早期泌乳期相似，HC 奶牛在清晨访问量最低时，还记录了更多的门卡（P<0.01）。关于用浓缩物补充奶牛的任何决定都需要从经济角度进行检查，以确定晚期泌乳时显示的产奶量和奶牛流量的好处是否超过浓缩物的成本；从而确保补充决定是谨慎的。
