Bergamasco Luciana, Edwards-Callaway Lily N, Bello Nora M, Mijares Sage H, Cull Charley A, Rugan Stacy, Mosher Ruby A, Gehring Ronette, Coetzee Johann F
Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA.
Department of Animal Science and Industry, College of Agriculture, Kansas State University, Manhattan, KS 66506, USA.
Animals (Basel). 2021 Sep 17;11(9):2719. doi: 10.3390/ani11092719.
The objective was to characterize physiological responses to unmitigated surgical castration in calves of varying ages. Thirty male Holstein calves of three ages [<6 w (6W); 3 m (3M); 6 m (6M); = 10] underwent a simulated castration treatment (SHAM) followed 24 h later by castration (CAST). For both treatments, heart rate variability, eye temperature, and cortisol were measured over time from treatment to specified end points to capture the acute response period. Interactions between treatment and age ( = 0.035) and time and age ( < 0.001) were noted for cortisol. The 6W calves had lower cortisol compared to 6M calves at SHAM and CAST. Cortisol of 6W calves decreased from peak to pre-treatment levels faster than 6M calves. An interaction between time and age was reported in squared differences of inter-beat-intervals (RMSSD; = 0.02) and high-frequency power (HFP; = 0.05), whereby both responses decreased in 6W calves during the sampling period which was not seen in 3M and 6M calves. Average eye temperature (AET) differed by age ( = 0.0018) whereby 6W calves had lower AET than 6M calves ( = 0.0013) regardless of treatment and time. The findings suggest that responses to unmitigated surgical castration seem to be mediated by the autonomic nervous system in an age-related manner.
目的是描述不同年龄犊牛在未缓解的手术去势过程中的生理反应。30头不同年龄的雄性荷斯坦犊牛[<6周龄（6W）；3月龄（3M）；6月龄（6M）；各10头]先接受模拟去势处理（假手术，SHAM），24小时后进行去势手术（CAST）。对于这两种处理，在从处理到指定终点的时间段内测量心率变异性、眼温及皮质醇水平，以捕捉急性反应期。皮质醇方面，观察到处理与年龄之间的交互作用（P = 0.035）以及时间与年龄之间的交互作用（P < 0.001）。在假手术和去势手术时，6W犊牛的皮质醇水平低于6M犊牛。6W犊牛的皮质醇从峰值降至处理前水平的速度比6M犊牛快。在相邻心搏间期的平方差（RMSSD；P = 0.02）和高频功率（HFP；P = 0.05）方面，报告了时间与年龄之间的交互作用，即在取样期间，6W犊牛的这两种反应均下降，而3M和6M犊牛未出现这种情况。平均眼温（AET）因年龄而异（P = 0.0018），无论处理和时间如何，6W犊牛的AET均低于6M犊牛（P = 0.0013）。研究结果表明，对未缓解的手术去势的反应似乎以与年龄相关的方式由自主神经系统介导。
