Nielsen P P, Jensen M B, Lidfors L
Department of Animal Environment and Health, Swedish University of Agricultural Sciences, PO Box 234, SE-532 23 Skara, Sweden.
J Dairy Sci. 2008 Jun;91(6):2423-32. doi: 10.3168/jds.2007-0666.
The aim of the present study was to investigate the effects of teat-feeding method and weaning method on behavior, milk and concentrate intake, and weight gain of group-housed dairy calves. Forty-eight calves were housed in groups of 4 and offered 6 L of whole milk per calf in 2 daily feedings. In 6 of the 12 group pens, the calves were offered the milk in a teat bar with a separate milk compartment for each teat, whereas in the remaining 6 pens, the calves were offered the milk in a teat bar with all teats connecting to 1 shared milk compartment. Calves were gradually weaned off milk by reducing the volume of milk over a 10-d period, starting at an average age of 47 d. In 6 pens (3 pens with each of the 2 milk-feeding treatments), calves were weaned by volume reduction, whereas in the remaining pens, the calves were weaned by diluting the milk with water (WD) and maintaining the same total volume of liquid. Daily concentrate intake per pen was recorded during weaning and 1 wk after weaning. Behavior was recorded around milk feeding, by direct observation on 1 occasion before and on 1 occasion during weaning, and by video on 1 occasion before and 2 occasions during weaning. Furthermore, the behavior was recorded during the 15 h of light on 1 occasion during weaning. Individual milk intake was measured twice by weighing the calves immediately before and after milk feeding. The calves fed via a separate teat bar switched between teats more often than calves fed with a shared teat bar. There was greater variation in the duration of ingesting milk within groups fed via a separate teat bar, but no effect of teat bar design was found on the variation in milk intake within the groups. Calves fed via a separate teat bar took longer to start eating concentrate after milk feeding than calves fed with a shared teat bar. The WD calves had a lower concentrate intake during weaning than weaned by volume reduction calves. The WD calves were lying down less during the 30 min after milk feeding and during the 15 h of light, although they had a shorter latency to lie down after milk feeding. In conclusion, a separate teat bar increased teat switching, increased variation in duration of ingesting milk, and increased the latency to eat concentrates after milk feeding. There was no effect of the teat bar design on feed intake or weight gain. However, weaning the calves by gradually diluting the milk with water reduced lying during weaning and reduced the concentrate intake during and after weaning.
本研究的目的是调查奶嘴喂养方法和断奶方法对群养奶牛犊行为、牛奶和精饲料摄入量以及体重增加的影响。48头犊牛以每组4头的方式饲养，每头犊牛每天分两次喂食6升全脂牛奶。在12个组栏中的6个里，给犊牛提供带有独立奶腔的奶嘴栏，每个奶嘴一个独立奶腔；而在其余6个组栏中，给犊牛提供所有奶嘴连接到一个共用奶腔的奶嘴栏。犊牛在平均47日龄时开始，通过在10天内减少牛奶量逐渐断奶。在6个组栏（两种牛奶喂养处理各3个组栏）中，犊牛通过减少量断奶，而在其余组栏中，犊牛通过用水稀释牛奶（WD）并保持相同的总液体量断奶。在断奶期间和断奶后1周记录每个组栏的每日精饲料摄入量。在喂奶前后各直接观察1次、断奶期间直接观察1次以及断奶前后各通过视频观察2次来记录断奶期间喂奶时的行为。此外，在断奶期间的1次光照15小时期间记录行为。通过在喂奶前后立即称犊牛体重来测量个体牛奶摄入量两次。通过独立奶嘴栏喂养的犊牛比通过共用奶嘴栏喂养的犊牛更频繁地在奶嘴间切换。通过独立奶嘴栏喂养的组内犊牛在喝奶持续时间上有更大的差异，但未发现奶嘴栏设计对组内牛奶摄入量差异有影响。通过独立奶嘴栏喂养的犊牛在喂奶后开始吃精饲料的时间比通过共用奶嘴栏喂养的犊牛长。WD犊牛在断奶期间的精饲料摄入量低于通过减少量断奶的犊牛。WD犊牛在喂奶后30分钟内和光照15小时期间躺卧较少，尽管它们在喂奶后躺卧的潜伏期较短。总之，独立奶嘴栏增加了奶嘴切换，增加了喝奶持续时间的差异，并增加了喂奶后吃精饲料的潜伏期。奶嘴栏设计对采食量或体重增加没有影响。然而，通过逐渐用水稀释牛奶使犊牛断奶会减少断奶期间的躺卧时间，并减少断奶期间及断奶后的精饲料摄入量。
