Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, WI 53706; Center for Animal Welfare, Department of Animal Science, University of California, Davis, Davis, CA 95616.
Center for Animal Welfare, Department of Animal Science, University of California, Davis, Davis, CA 95616.
J Dairy Sci. 2023 Sep;106(9):6365-6374. doi: 10.3168/jds.2023-23237. Epub 2023 Jul 26.
Hot-iron disbudding, the practice of cauterizing horn bud tissue to prevent horn growth in dairy calves, results in behavioral changes indicative of pain in the first few days after the procedure. However, few studies have quantified behavioral changes in the following weeks, while the burn wounds are still healing. Female Holstein calves were disbudded with a heated iron and pain relief (5.5 mL lidocaine cornual nerve block and 1 mg/kg oral meloxicam) at 4 to 10 d of age (n = 19) or not disbudded (n = 19). Calves wore ear tag accelerometers that reported the dominant behavior being performed at 1-min intervals from 3 to 21 d after disbudding. Compared with age-matched controls, disbudded calves tended to spend more time inactive throughout the observation period, ruminated less in the first 3 to 11 d after disbudding, and sucked more from a milk bottle beginning 5 d after disbudding until the end of the 21-d observation period. In addition to the accelerometer data, live observations of sleeping (using a behavioral proxy), lying, and ruminating were collected using instantaneous sampling at 5-min intervals for 24-h periods 3, 10, and 17 d after disbudding. Disbudded calves slept with their head down more on all live observation days and spent more time lying on the 17th d after disbudding, but ruminating did not differ compared with controls, in contrast to the accelerometer results. More time spent inactive, sleeping, and lying, and less time spent ruminating (as indicated by the accelerometer) can be interpreted as attempts to reduce painful stimulation of the disbudding wounds and allocate energy to healing. It is unclear whether the greater amount of sucking in the disbudded calves is nutritive (milk present) or non-nutritive (milk absent), as the algorithm did not distinguish the type of sucking, and further research is needed to explore the factors underlying this effect. We conclude that disbudding alters daily behavior patterns for at least 3 wk, far beyond the duration of recommended pain medication, raising additional welfare concerns about the procedure.
热铁烙角，即通过灼烧角芽组织来阻止奶牛小牛角的生长，会导致小牛在手术后的头几天出现疼痛相关的行为变化。然而，很少有研究对手术后接下来的几周内的行为变化进行量化，此时烧伤伤口仍在愈合。4 至 10 日龄时，给 19 头荷斯坦小母牛使用加热铁烙和止痛剂（5.5 毫升利多卡因角状神经丛阻滞和 1 毫克/千克口服美洛昔康）进行烙角，并将其与未烙角的 19 头小母牛进行对照。术后 3 至 21 天内，给小牛佩戴耳标加速度计，以 1 分钟为间隔记录其主要行为。与同龄对照相比，烙角后的小牛在整个观察期间倾向于更多时间处于静止状态，烙角后 3 至 11 天内反刍次数更少，并且从烙角后 5 天开始，会更多地从奶瓶中吸吮，直至 21 天观察期结束。除了加速度计数据之外，还通过行为替代物收集了睡眠（实时观察）、躺着和反刍的实时观察数据，在烙角后 3、10 和 17 天，使用 5 分钟的瞬时采样，对 24 小时内的数据进行了收集。与对照组相比，烙角后的小牛在所有实时观察日都更倾向于低头睡觉，在烙角后 17 天躺着的时间也更多，但是与加速度计结果相反，反刍并没有差异。更多时间的静止、睡眠和躺着，以及更少的反刍（由加速度计指示）可以被解释为试图减少烙角伤口的疼痛刺激，并将能量分配到伤口愈合中。由于算法无法区分吮吸的类型，因此尚不清楚烙角后的小牛吮吸的次数增加是否是营养性的（有奶）还是非营养性的（无奶），还需要进一步的研究来探索这种效应的潜在因素。我们的结论是，烙角至少会在 3 周内改变小牛的日常行为模式，远远超过了推荐的止痛药物持续时间，这进一步引发了对该程序的额外福利关注。
