Ren Xiaoli, Lu Haibo, Wang Yachun, Yan Lei, Liu Changlei, Chu Chu, Yang Zhuo, Bao Xiangnan, Yu Mei, Zhang Zhen, Zhang Shujun
Frontiers Science Center for Animal Breeding and Sustainable Production, Huazhong Agricultural University, Wuhan 430070, China.
Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan 430070, China.
Animals (Basel). 2024 Aug 15;14(16):2372. doi: 10.3390/ani14162372.
Mastitis (MAS), endometritis (MET), and ketosis (KET) are prevalent diseases in dairy cows that result in substantial economic losses for the dairy farming industry. This study gathered 26,014 records of the health and sickness of dairy cows and 99,102 data of reproduction from 13 Holstein dairy farms in Central China; the milk protein and milk fat content from 56,640 milk samples, as well as the pedigree data of 37,836 dairy cows were obtained. The logistic regression method was used to analyze the variations in the prevalence rates of MAS, MET, and KET among various parities; the mixed linear model was used to examine the effects of the three diseases on milk production, milk quality, and reproductive traits. DMU software (version 5.2) utilized the DMUAI module in conjunction with the single-trait and two-trait animal model, as well as best linear unbiased prediction (BLUP), to estimate the genetic parameters for the three diseases, milk production, milk quality, and reproductive traits in dairy cows. The primary findings of the investigation comprised the following: (1) The prevalence rates of MAS, MET, and KET in dairy farms were 20.04%, 10.68%, and 7.33%, respectively. (2) MAS and MET had a substantial impact ( 0.01) on milk production, resulting in significant decreases of 112 kg and 372 kg in 305-d Milk Yield (305-d MY), 4 kg and 12 kg in 305-d Protein Yield (305-d PY), and 6 kg and 16 kg in 305-d Fat Yield (305-d FY). As a result of their excessive 305-d MY, some cows were diagnosed with KET due to glucose metabolism disorder. The 305-d MY of cows with KET was significantly higher than that of healthy cows (205 kg, 0.01). (3) All three diseases resulted in an increase in the Interval from Calving to First Service (CTFS, 0.60-1.50 d), Interval from First Service to Conception (FSTC, 0.20-16.20 d), Calving Interval (CI, 4.00-7.00 d), and Number of Services (NUMS, 0.07-0.35). (4) The heritabilities of cows with MAS, MET, and KET were found to be low, with values of 0.09, 0.01, and 0.02, respectively. The genetic correlation between these traits ranged from 0.14 to 0.44. This study offers valuable insights on the prevention and control of the three diseases, as well as feeding management and genetic breeding.
乳腺炎（MAS）、子宫内膜炎（MET）和酮病（KET）是奶牛的常见疾病，给奶牛养殖业造成了巨大的经济损失。本研究收集了中国中部13个荷斯坦奶牛场26014条奶牛健康与疾病记录、99102条繁殖数据；获取了56640份牛奶样本的乳蛋白和乳脂含量，以及37836头奶牛的系谱数据。采用逻辑回归方法分析不同胎次中MAS、MET和KET患病率的变化；使用混合线性模型研究这三种疾病对产奶量、牛奶品质和繁殖性状的影响。DMU软件（版本5.2）利用DMUAI模块结合单性状和双性状动物模型以及最佳线性无偏预测（BLUP），估计奶牛这三种疾病、产奶量、牛奶品质和繁殖性状的遗传参数。调查的主要结果如下：（1）奶牛场中MAS、MET和KET的患病率分别为20.04%、10.68%和7.33%。（2）MAS和MET对产奶量有重大影响（P<0.01），导致305天产奶量（305-d MY）显著下降112千克和372千克，305天蛋白产量（305-d PY）分别下降4千克和12千克，305天脂肪产量（305-d FY）分别下降6千克和16千克。由于部分奶牛305-d MY过高，因葡萄糖代谢紊乱被诊断为患KET。患KET奶牛的305-d MY显著高于健康奶牛（205千克，P<0.01）。（3）这三种疾病均导致产犊至首次配种间隔（CTFS，增加0.60-1.50天）、首次配种至受孕间隔（FSTC，增加0.20-16.20天）、产犊间隔（CI，增加4.00-7.00天）和配种次数（NUMS，增加0.07-0.35）。（4）发现患MAS、MET和KET奶牛的遗传力较低，分别为0.09、0.01和0.02。这些性状之间的遗传相关性在0.14至0.44之间。本研究为这三种疾病的防控以及饲养管理和遗传育种提供了有价值的见解。
