Norring Marianna, Mintline Erin M, Tucker Cassandra B
Research Centre for Animal Welfare, Faculty of Veterinary Medicine, University of Helsinki, FI-00014 Helsinki, Finland.
Center for Animal Welfare, Department of Animal Science, University of California, Davis 95616.
Transl Anim Sci. 2017 Sep 1;1(3):358-366. doi: 10.2527/tas2017.0044. eCollection 2017 Sep.
Castration is painful for calves. Castrating at an earlier age is often recommended, but little is known about how this affects the healing process or the pain experienced. We compared incision closure, swelling and pain sensitivity of beef calves surgically castrated at 3 (range 0 to 8 d; = 16) or 73 (range 69 to 80 d; = 15) d of age. Closure of the incision, as measured with a 5-point scale (1 = fresh wound, 5 = no longer visible), weight gain, and inflammation (skin temperature and swelling, as measured by scrotal circumference) were recorded on d 1, 3, 7, 11, 15, 18, 21, 25, 32, 39, 45, 61, and 77 after the procedure, until all incisions were fully healed. On these same days, pain sensitivity was assessed by applying a known and increasing force with von Frey hairs (0.02 to 300 g-force) at the edge of the castration wound and at a control site, approximately 2 to 5 cm anterior to the teats, until animals showed a behavioral response or the highest force was reached. The incisions of younger calves healed more quickly than older ones [fully healed, median (95% confidence interval); 39 (32 to 61) vs. 61 (61 to 77) d; = 0.002], however, they had relatively more swelling in the days after castration ( < 0.001). Younger animals reacted to lighter pressure of von Frey hairs compared to older calves especially in the first stages of healing process ( < 0.001), and there were other signs indicative of inflammation processes in this region at this time. However, there was no difference in the control site for either age group. In addition, it took longer for older calves to recover their daily weight gain after the procedure ( < 0.001). Taken together, these results paint a mixed picture about the effects of age of surgical castration. Calves castrated soon after birth experience more tissue swelling and show more signs of pain, but their incisions heal sooner and their weight gain is less affected, when compared to animals castrated around 73 d of age.
去势对犊牛来说是痛苦的。通常建议在犊牛较小的时候进行去势，但对于这如何影响愈合过程或所经历的疼痛却知之甚少。我们比较了在3日龄（范围0至8天；n = 16）或73日龄（范围69至80天；n = 15）接受手术去势的肉牛犊的切口闭合情况、肿胀程度和疼痛敏感性。在手术后的第1、3、7、11、15、18、21、25、32、39、45、61和77天记录切口闭合情况（用5分制衡量，1 = 新鲜伤口，5 = 不再可见）、体重增加情况以及炎症（通过阴囊周长测量皮肤温度和肿胀程度），直至所有切口完全愈合。在这些相同的日子里，通过在去势伤口边缘和一个对照部位（乳头前方约2至5厘米处）用von Frey毛发施加已知且逐渐增加的力（0.02至300克力）来评估疼痛敏感性，直到动物表现出行为反应或达到最大力。较年幼犊牛的切口比较年长犊牛愈合得更快[完全愈合，中位数（95%置信区间）；39（32至61）天对61（61至77）天；P = 0.002]，然而，在去势后的几天里它们的肿胀相对更严重（P < 0.001）。与较年长犊牛相比，较年幼的动物对von Frey毛发较轻的压力就有反应，尤其是在愈合过程的最初阶段（P < 0.001），并且此时该区域还有其他炎症过程的迹象。然而，两个年龄组在对照部位没有差异。此外，较年长犊牛在手术后恢复每日体重增加所需的时间更长（P < 0.001）。综合来看，这些结果对于手术去势年龄的影响描绘了一幅复杂的图景。与73日龄左右去势的动物相比，出生后不久就去势的犊牛会经历更多的组织肿胀并表现出更多的疼痛迹象，但它们的切口愈合更快且体重增加受影响较小。
