Aarhus University, Department of Animal Science, Blichers Allé 20, DK-8830 Tjele, Denmark.
Wageningen University & Research, Animal Production Systems group, Department of Animal Science, PO Box 338, 6700AH, Wageningen, the Netherlands.
J Dairy Sci. 2022 Jul;105(7):6196-6206. doi: 10.3168/jds.2021-21614. Epub 2022 May 5.
Under natural conditions, most parturient cows seek visual cover or seclude themselves from the herd when calving becomes imminent. Studies on calving site selection of dairy cows housed indoors show that predominantly older and dominant cows calve in secluded areas. This study aimed to investigate whether cows distance themselves further from herd members under spacious outdoor conditions and whether artificial hides on a pasture motivate cows to seek visual isolation from the herd. One hundred eighty-two Danish Holstein cows were allocated to 1 of 13 groups of 14 cows according to expected calving date. In 2 paddocks (each 75 × 150 m), 5 zones (75 m × 30 m) were defined; zone 0 contained the feeding and shade area, and zone 4 bordered an area with trees. Weekly and according to calving date, a group of 14 cows was moved either to a paddock that had 12 hides distributed evenly throughout zones 1 to 4 (7 groups) or to a paddock without hides (6 groups). The hides were wooden structures (3.3 m long × 1.0 m wide × 1.2 m high) that the cows could hide behind. One hundred seven cows calved within 14 d of having been moved to the paddock, and 82 of these (38 primiparous and 44 multiparous), and their calves, were included in the study. From 3 h before until 3 h after calving, the location, posture, and behavior of cows were recorded continuously from video recordings. In addition, location, posture, and behavior of the calves were recorded for the first 3 h after birth. Continuous variables were analyzed by linear mixed effects models, whereas binary data were analyzed using mixed effects logistic regression. The presence of hides did not affect selection of calving location in the paddock, but more primiparous than multiparous cows calved in zone 4; that is, furthest away from the feeding area. Before calving, primiparous cows were more likely to be positioned in zone 4 and less likely to approach and contact herd members. After calving, primiparous cows and their calves tended to be more likely to be positioned in zone 4. The more cows present in the paddock, the less likely the cows were to isolate (i.e., be further than 30 m away from any other cow) at the time of calving. In addition, the more cows in the paddock when a calf was born, the less time these calves spent in a lying posture. The results show that primiparous cows move further away from herd members at calving than multiparous cows and suggest that primiparous cows prefer to isolate themselves through distance rather than seeking artificial cover. Contrary to expectation, the hides did not make more cows select a calving site away from the feeding area.
在自然条件下，大多数分娩的奶牛在即将分娩时会寻找视觉掩护或与牛群隔离。对室内饲养奶牛的分娩地点选择的研究表明，主要是年龄较大和占优势的奶牛在隐蔽的地方分娩。本研究旨在调查在宽敞的户外条件下，奶牛是否会与牛群成员进一步分离，以及牧场上的人工隐蔽处是否会促使奶牛与牛群隔离。182 头丹麦荷斯坦奶牛根据预期的分娩日期分配到 13 个 14 头奶牛组中的 1 个。在 2 个围场（每个 75×150 m）中，定义了 5 个区域（75 m×30 m）；区域 0 包含饲料和遮荫区，区域 4 与树木接壤。每周并根据分娩日期，将 14 头奶牛的一组移动到一个围场，该围场有 12 个隐蔽物均匀分布在区域 1 到 4（7 个组），或移动到一个没有隐蔽物的围场（6 个组）。隐蔽物是奶牛可以藏身的木制结构（3.3 m 长×1.0 m 宽×1.2 m 高）。107 头奶牛在转移到围场后 14 天内分娩，其中 82 头（38 头初产和 44 头经产）及其小牛被纳入研究。从分娩前 3 小时到分娩后 3 小时，连续从视频记录中记录奶牛的位置、姿势和行为。此外，还记录了小牛出生后 3 小时内的位置、姿势和行为。连续变量通过线性混合效应模型进行分析，而二元数据则通过混合效应逻辑回归进行分析。隐蔽物的存在并不影响围场中分娩地点的选择，但初产奶牛比经产奶牛更倾向于在区域 4 分娩；也就是说，离饲料区最远。分娩前，初产奶牛更有可能位于区域 4，不太可能接近和接触牛群成员。分娩后，初产奶牛及其小牛往往更容易位于区域 4。围场内的奶牛越多，奶牛在分娩时隔离（即与任何其他奶牛的距离超过 30 m）的可能性就越小。此外，当小牛出生时，围场内的奶牛越多，小牛处于躺卧姿势的时间就越短。研究结果表明，初产奶牛在分娩时比经产奶牛离牛群成员更远，这表明初产奶牛更喜欢通过距离来隔离自己，而不是寻求人工掩护。与预期相反，隐蔽物并没有使更多的奶牛选择远离饲料区的分娩地点。
