1MTT Agrifood Research Finland, Animal Production Research, Vakolantie 55, 03400 VIHTI, Finland.
Animal. 2011 Mar;5(3):428-32. doi: 10.1017/S1751731110001928.
We developed a method for studying the synchrony of behaviour based on calculations of overdispersion of a binomial process. The lying behaviour of cows was investigated under two different housing units inside the same barn. The first unit housed 30 cows undergoing conventional milking and the second unit housed 27 cows undergoing automatic milking. The lying behaviour of the cows was observed over 3 weeks in 12 periods of 6 h each. Every 5 min, we counted the number of cows lying down in the cubicles. As external cues, like feeding and conventional milking, can promote synchrony in dairy cows, we expected that cows conventionally milked would show more behavioural synchrony than automatically milked cows. Cows lied down synchronously in both units (overdispersion 1.67, P < 0.01). Lying synchrony tended to be slightly bigger in automatically than in conventionally milked cows (overdispersion 1.76 v. 1.58, P = 0.09), although the proportion of cows lying down was on average greater in conventionally than in automatically milked cows (60.7% v. 45.6%). This suggests that synchronized lying behaviour in cows is a constant phenomenon that depends on social facilitation rather than on external cues. The overdispersion index appears to be a useful tool for studying the synchrony of animal behaviour when observations are made at the group level.
我们开发了一种基于二项式过程离差过度计算来研究行为同步性的方法。在同一个畜舍内的两个不同畜栏中，研究了奶牛的躺卧行为。第一个畜栏饲养了 30 头正在接受常规挤奶的奶牛，第二个畜栏饲养了 27 头正在接受自动挤奶的奶牛。在 3 周的时间里，对奶牛的躺卧行为进行了 12 次 6 小时的观察。每 5 分钟，我们会统计卧在牛栏里的奶牛数量。由于外部线索，如喂食和常规挤奶，会促进奶牛的同步性，我们预计常规挤奶的奶牛会比自动挤奶的奶牛表现出更多的行为同步性。在两个畜栏中，奶牛的躺卧行为都呈现出同步性（过度离散度 1.67，P<0.01）。自动挤奶的奶牛比常规挤奶的奶牛的躺卧同步性略高（过度离散度 1.76 比 1.58，P=0.09），尽管平均而言，常规挤奶的奶牛躺下的比例高于自动挤奶的奶牛（60.7%比 45.6%）。这表明，奶牛的同步躺卧行为是一种恒定现象，取决于社会促进，而不是外部线索。当在群体水平上进行观察时，过度离散度指数似乎是研究动物行为同步性的有用工具。
