Valníčková Barbora, Bartošová Jitka, Bartoš Luděk
Department of Ethology, Institute of Animal Science, 104 00 Praha, Czech Republic.
Animals (Basel). 2024 Nov 29;14(23):3459. doi: 10.3390/ani14233459.
Feral cattle () live in socially stable herds. Due to farm management practices, intensively managed dairy cows experience frequent regrouping, which can disrupt affiliative bonds and induce social stress. This study examines how changes in herd composition affect milk yield and udder health traits in resident dairy cows exposed to the withdrawal of herd members or the introduction of new individuals. Milk yield, electrical conductivity, and blood presence in milk were measured in 798 cows using precision dairy sensors over 9 years. Milk yield decreased significantly ( < 0.001) one day after the removal of familiar herd members, while introducing cows had no effect. A higher number of cows being withdrawn (up to 10) was associated with reduced milk yield ( < 0.001), elevated milk electrical conductivity ( = 0.01), and an increased prevalence of blood presence in milk ( = 0.01), which can indicate potential udder health issues linked to social stress. Holstein Friesian, primiparous, and first-lactation-stage cows were more affected than Czech Simental and multiparous cows later in lactation. These findings underscore the influence of social stability on dairy cow welfare and productivity, emphasising the need for strategies to mitigate stress when herd changes are necessary.
野生牛群生活在社会结构稳定的群体中。由于农场管理方式的原因，集约化管理的奶牛经常会重新分组，这可能会破坏亲和关系并引发社会压力。本研究考察了群体组成的变化如何影响那些经历了群体成员撤离或新个体引入的常住奶牛的产奶量和乳房健康特征。在9年时间里，使用精准奶牛传感器对798头奶牛的产奶量、电导率和牛奶中的血液含量进行了测量。在熟悉的群体成员被撤离后的一天，产奶量显著下降（<0.001），而引入奶牛则没有影响。更多数量的奶牛被撤离（最多10头）与产奶量降低（<0.001）、牛奶电导率升高（=0.01）以及牛奶中血液出现的患病率增加（=0.01）有关，这可能表明与社会压力相关的潜在乳房健康问题。荷斯坦弗里生奶牛、初产奶牛和第一泌乳期奶牛比捷克西门塔尔奶牛和泌乳后期的经产奶牛受到的影响更大。这些发现强调了社会稳定性对奶牛福利和生产力的影响，突出了在必要进行群体变动时减轻压力策略的必要性。
