肉牛难产主要因素分析

Analysis of Dystocia-Related Factors in Beef Cattle

难产(dystocia)是母畜分娩时胎儿娩出缓慢或难以娩出,需要助产帮助胎儿娩出的过程。难产既会导致母牛出现生殖道疾病而影响其后的发情和繁殖,也会危及犊牛和母牛的生命,严重损害养牛经济效益。引起肉牛难产的因素很多,有遗传因素和非遗传因素,包括母牛因素、胎儿因素、公牛因素、营养因素与环境因素等。犊牛出生重、母体骨盆结构和妊娠时长是3个最主要的因素。多种因素的交叉互作,使难产成为极其复杂的生理与病理现象。国际牛业发达国家非常重视母牛繁殖与生产环节,开展了大量卓有成效的研究与分析。在对几十年来有关肉牛繁殖与生产方面的报道较为细致分析基础上,文章重点对普通肉牛繁殖与生产过程中出现的主要难产问题进行综述,供国内同行借鉴。

Dystocia is a prolonged and difficult parturition requiring the use of specialist instruments, which is of great economic importance due to the cost of treatment increasing together with an increase in difficulty of the first and subsequent calving or even the death of calves and cows. There are many factors that cause dystocia in beef cattle, including genetic factors and non-genetic factors, such as cow factors, fetal factors, bull factors, nutritional factors and environmental factors. Calf birth weight, maternal pelvic size and gestation length are the three most important factors. The interplays of these factors make dystocia a very complicated physiological and pathological phenomenon. In the developed countries of beef cattle industry, beef cattle researchers and industries pay great attention to cow reproduction, and have carried out a lot of fruitful researches and analyses. Based on a detailed analysis of the international reports on beef cattle breeding and production in the past decades, especially the data from developed countries, the problems of dystocia during the process of beef cattle breeding and production were comprehensively reviewed, which would provide reference for domestic beef cattle practitioners.