Canozzi Maria Eugênia Andrighetto, Mederos America, Manteca Xavier, Turner Simon, McManus Concepta, Zago Daniele, Barcellos Júlio Otávio Jardim
Department of Animal Science, Federal University of Rio Grande do Sul, Bento Gonçalves Ave., no 7712, 91540-000 Porto Alegre, RS, Brazil.
National Research Institute for Agriculture, Ruta 5 km 386, Tacuarembo 45000, Uruguay.
Res Vet Sci. 2017 Oct;114:430-443. doi: 10.1016/j.rvsc.2017.07.014. Epub 2017 Jul 20.
A systematic review and meta-analysis (MA) were performed to summarize all scientific evidence for the effects of castration in male beef cattle on welfare indicators based on cortisol concentration, average daily gain (ADG), and vocalization. We searched five electronic databases, conference proceedings, and experts were contacted electronically. The main inclusion criteria involved completed studies using beef cattle up to one year of age undergoing surgical and non-surgical castration that presented cortisol concentration, ADG, or vocalization as an outcome. A random effect MA was conducted for each indicator separately with the mean of the control and treated groups. A total of 20 publications reporting 26 studies and 162 trials were included in the MA involving 1814 cattle. Between study heterogeneity was observed when analysing cortisol (I=56.7%) and ADG (I=79.6%). Surgical and non-surgical castration without drug administration compared to uncastrated animals showed no change (P≥0.05) in cortisol level. Multimodal therapy for pain did not decrease (P≥0.05) cortisol concentration after 30min when non-surgical castration was performed. Comparison between surgical castration, with and without anaesthesia, showed a tendency (P=0.077) to decrease cortisol levels after 120min of intervention. Non-surgical and surgical castration, performed with no pain mitigation, increased and tended to increase the ADG by 0.814g/d (P=0.001) and by 0.140g/d (P=0.091), respectively, when compared to a non-castrated group. Our MA study demonstrates an inconclusive result to draw recommendations on preferred castration practices to minimize pain in beef cattle.
进行了一项系统评价和荟萃分析（MA），以总结基于皮质醇浓度、平均日增重（ADG）和发声情况，对雄性肉牛去势影响福利指标的所有科学证据。我们检索了五个电子数据库、会议论文集，并通过电子邮件联系了专家。主要纳入标准包括对一岁以下肉牛进行手术和非手术去势的完整研究，这些研究将皮质醇浓度、ADG或发声作为结果指标。对每个指标分别进行随机效应MA，计算对照组和处理组的均值。MA共纳入20篇报道26项研究和162次试验的出版物，涉及1814头牛。分析皮质醇（I=56.7%）和ADG（I=79.6%）时观察到研究间存在异质性。与未去势动物相比，未用药的手术和非手术去势在皮质醇水平上无变化（P≥0.05）。进行非手术去势时，疼痛多模式治疗在30分钟后并未降低（P≥0.05）皮质醇浓度。有麻醉和无麻醉的手术去势干预120分钟后，皮质醇水平有降低趋势（P=0.077）。与未去势组相比，未缓解疼痛的非手术和手术去势分别使ADG增加0.814g/d（P=0.001）和有增加趋势（P=0.091），增加0.140g/d。我们的MA研究结果尚无定论，无法就首选的去势方法提出建议以尽量减少肉牛的疼痛。
