Research Laboratory of Ecosystems & Aquatic Resources, National Agronomic Institute of Tunisia, Carthage University, 43 Avenue Charles Nicolle, Tunis 1082, Tunisia.
Department of Animal Production, Ecole Nationale de Médecine Vétérinaire de Sidi Thabet, Sidi Thabet 2020, Tunisia.
Genes (Basel). 2023 Mar 8;14(3):670. doi: 10.3390/genes14030670.
In Tunisia, the recognition of the possibility of including longevity and disease resistance in dairy cattle selection objectives has been hypothesized as a useful strategy by both researchers and producers. However, in this paper, the state of the art, with a focus on health and longevity, is reviewed. Along the same lines, the heritability for the milk traits, fertility traits, and longevity of Tunisian Holstein dairy cows complies with the literature. Therefore, the influence of genetics on some diseases of the dairy cow was investigated. In addition, a decreasing efficiency in cow fertility has been observed over the last few years. The results showed that the risk of culling increased with common diseases. When analyzed with the Weibull model, functional lifespan was strongly influenced by milk yield; therefore, the risk increased with a reduced milk yield. In her first three lactations, the relative risk of selection increased gradually with lactation. Thus, the risk of thinning is highest at the beginning and end of the first feeding and the end of her second feeding. In conclusion, the risk of culling was reduced in parity. The factors that influence the life of the herd, such as health, husbandry, environmental conditions, and management, are often ignored when evaluating longevity.
在突尼斯，研究人员和生产者都假设，将长寿和疾病抗性纳入奶牛选择目标的可能性是一种有用的策略。然而，本文主要关注健康和长寿，回顾了这方面的最新研究进展。同样，突尼斯荷斯坦奶牛的产奶量、繁殖力和寿命等性状的遗传力与文献相符。因此，研究了遗传因素对奶牛某些疾病的影响。此外，近年来发现奶牛的繁殖效率呈下降趋势。结果表明，淘汰风险随着常见疾病的增加而增加。用威布尔模型分析时，功能寿命受产奶量的强烈影响，因此，随着产奶量的减少，风险增加。在最初的三个泌乳期中，随着泌乳期的增加，选择的相对风险逐渐增加。因此，在第一次和第二次泌乳的开始和结束时，变薄的风险最高。总之，胎次对淘汰风险有影响。在评估奶牛寿命时，常常忽略了影响牛群寿命的因素，如健康、饲养、环境条件和管理等。
