Risks associated to different methods of increasing pregnancy rate of cows in cow-calf systems

ABSTRACT This study assessed the risks of different management practices to increase pregnancy rate in beef cow-calf systems, aiming at assisting decision-making. The perception of 18 experts on animal sciences regarding the risks of 32 nutritional, breeding, and general management practices applied to increase pregnancy rate were evaluated through questionnaires. The experts were selected by a non-probability sampling of researchers on veterinary and animal sciences. In addition, five farmers and eight technical consultants were also selected. The questionnaire was applied during a face-to-face meeting. The risk of each practice was assessed according to four factors, namely, cost, technical knowledge, operational complexity, and flexibility, and an equation was developed to calculate this risk. The applied method allowed to determine the risk of each practice, obtaining results similar to those previously perceived by the experts. Operational complexity and cost had greater influence on the estimated risks compared with the other factors. Moreover, the increase of one unit in operational complexity and cost increased the perceived risk and the estimated risk scores in 0.43 and 0.28 points, respectively. Overall, the application of general management practices presented lower risk score compared with nutritional and breeding practices, which were not different from which other. Equations to estimate the risks of farm managers should routinely apply management practices to increase the efficiency of cow-calf production systems.

摘要：本研究评估了肉牛母牛-犊牛生产系统（beef cow-calf systems）中，用于提升受胎率的不同管理措施所存在的风险，旨在为决策提供辅助。研究通过问卷形式，评估了18位动物科学领域专家对32项用于提升受胎率的营养、繁育及常规管理措施的风险认知。专家样本通过非概率抽样选取自兽医与动物科学领域的研究者，同时还纳入了5位牧场主与8位技术顾问。问卷采用面对面方式发放。每项措施的风险从成本、技术知识要求、操作复杂度及灵活性四个维度进行评估，并开发了用于计算该风险的方程。所采用的方法可确定每项措施的风险，所得结果与专家此前的认知相符。相较于技术知识要求与灵活性这两个评估维度，操作复杂度与成本对风险评估结果的影响更大。具体而言，操作复杂度与成本每提升1个单位，专家感知的风险与模型评估的风险得分将分别增加0.43与0.28分。总体而言，常规管理措施的风险得分低于营养与繁育类措施，且这两类措施的风险得分并无显著差异。综上，可将用于估算风险的方程常规应用于各类提升肉牛母牛-犊牛生产系统效率的管理实践中。