Department of Animal Biosciences.
Department of Population Medicine, University of Guelph, Guelph, Ontario, N1G 2W1, Canada.
J Dairy Sci. 2017 Jun;100(6):4818-4828. doi: 10.3168/jds.2016-12281. Epub 2017 Apr 21.
This study evaluated differences in behavior and productivity between lame and nonlame cows in herds with automated milking systems (AMS). We monitored 30 cows per herd on 41 farms with AMS in Canada (26 herds in Ontario and 15 herds in Alberta). During a 6-d period, milking data (n = 1,184) and lying behavior data (n = 1,209) were collected from cows on 41 farms. Rumination behavior (n = 569) and activity (n = 615) data were available for cows at 22 farms. Locomotion was scored using a numerical rating system (NRS; 1 = sound; 5 = extremely lame). Cows were defined as clinically lame with NRS ≥ 3 (n = 353, 29%) and nonlame with NRS < 3 (n = 865, 71%). Greater parity, lower body condition, and lower environmental temperature were factors associated with lameness. When accounting for other factors, lame cows produced 1.6 kg/d less milk in 0.3 fewer milkings/d. Lame cows were 2.2 times more likely to be fetched more than 1 time during the 6-d period and spent 38 min/d more time lying down in bouts that were 3.5 min longer in comparison with nonlame cows. As the number of cows per AMS unit increased, the frequency of milkings and refusals per cow per day decreased and cow activity increased. For each 13.3-percentage-point increase in freestall stocking density (cows per stall), daily lying time decreased by 13 min/d and cows were 1.6 times more likely to be fetched more than 1 time during the 6-d period. There was no difference in daily rumination or activity between lame and nonlame cows or in night:day rumination time, but lame cows had greater night:day activity ratios. This study supports the growing knowledge that lameness has negative effects on milk production, voluntary milking behavior, and lying behavior of cows in herds with AMS. These results may help dairy producers gain a better appreciation of the negative effects of even moderate cases of lameness and may help motivate them to improve their lameness monitoring and treatment protocols.
本研究评估了在配备自动挤奶系统 (AMS) 的牛群中，跛行牛与非跛行牛在行为和生产性能方面的差异。我们在加拿大的 41 个配备 AMS 的农场（安大略省 26 个牛群，艾伯塔省 15 个牛群）中，对每个牛群中的 30 头奶牛进行了监测。在 6 天的时间内，从 41 个农场的奶牛身上收集了挤奶数据（n = 1184）和卧息行为数据（n = 1209）。在 22 个农场，反刍行为（n = 569）和活动（n = 615）数据可用于奶牛。使用数字评分系统（NRS；1 = 正常；5 = 非常跛行）对运动情况进行评分。将 NRS≥3（n = 353，29%）的奶牛定义为临床跛行，NRS＜3（n = 865，71%）的奶牛定义为非跛行。更高的胎次、更低的体况和更低的环境温度是跛行的相关因素。在考虑其他因素的情况下，跛行奶牛每天的产奶量减少 1.6 公斤，挤奶次数减少 0.3 次。与非跛行奶牛相比，跛行奶牛在 6 天的时间内被挤奶的次数多 2.2 倍，卧息时间长 3.5 分钟，卧息时间长 38 分钟。随着每个 AMS 单位中的奶牛数量增加，每头奶牛每天的挤奶和拒奶次数减少，奶牛的活动量增加。每增加 13.3 个百分点的畜栏占有率（每头奶牛的畜栏数），奶牛的每日卧息时间就会减少 13 分钟，在 6 天的时间内，奶牛被挤奶的次数多 1.6 倍的可能性增加。跛行牛与非跛行牛的每日反刍或活动时间以及夜间与白天的反刍时间没有差异，但跛行牛的夜间与白天活动比例更高。本研究支持了这样一种日益增长的认识，即跛行对产奶量、自愿挤奶行为和 AMS 牛群中的卧息行为有负面影响。这些结果可能有助于奶农更好地了解即使是中度跛行的负面影响，并可能有助于激励他们改善跛行监测和治疗方案。
