College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, P. R. China.
Joint International Research Laboratory of Agriculture and Agri-product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, 225009, P. R. China.
BMC Vet Res. 2024 Mar 8;20(1):85. doi: 10.1186/s12917-024-03931-1.
Comprehending the correlation between body conformation traits of cows at the early stages of lactation and prevalent lactation diseases might facilitate the execution of selection and feeding strategies that prioritize cow health. This study aimed to evaluate the impact of body conformation traits on the incidence of clinical mastitis and lameness in Chinese Holstein cows. From a pasture herd of 1472 early lactating Chinese Holstein cows, we evaluated 20 body conformation traits. During lactation, this pasture herd was visited weekly to gather clinical mastitis and lameness data. A nine-point scale was used to determine the conformation traits of cows to clarify their linear characters, including frame capacity, rump (RU), feet and leg (FL), mammary system (MS), and dairy character. A longitudinal binary disease (0 = healthy; 1 = diseased) data structure was created by allocating disease records to adjacent official test dates. The impact of body conformation traits on the risk of developing diseases (clinical mastitis and lameness) was analyzed using the logistic regression models.
Compared to cows with low total scores (75-79 points), those with high total scores (80-85 points) of body conformation traits had a significantly lower risk of mastitis (P < 0.001). The disease status (0 or 1: binary variable) of clinical mastitis in lactating cows was significantly impacted negatively by age (P < 0.05). The fore udder attachment (FUA), angularity, rear attachment height (RAH), and rear teat placement (RTP) were all significantly associated with clinical mastitis during lactation (P < 0.05). The rear leg-rear view (RLRV) was significantly correlated with correlated considerably (P < 0.05) with lameness during lactation. An ideal score of four points on the lameness risk dimension of the RLRV may indicate a low risk of lameness. Since the risk of mastitis decreased as this trait score increased, the RTP may be an ideal marker for mastitis risk.
According to the study, clinical mastitis and lameness risks in cows can be estimated using their body conformation traits. Cows with more centrally located rear teats have a lower risk of mastitis. These results may help dairy farmers identify cows at high risk of disease early in lactation and aid in breeding for disease resistance in cows.
了解泌乳早期奶牛体型特征与常见泌乳疾病之间的相关性，有助于实施以奶牛健康为重点的选择和饲养策略。本研究旨在评估体型特征对中国荷斯坦奶牛临床型乳腺炎和蹄病发病率的影响。从一个 1472 头泌乳早期中国荷斯坦奶牛的放牧牛群中，我们评估了 20 个体型特征。在泌乳期间，每周都会对放牧牛群进行一次访问，以收集临床型乳腺炎和蹄病的数据。使用九点量表来确定奶牛的体型特征，以明确其线性特征，包括体躯容量、尻部（RU）、后躯（FL）、乳房系统（MS）和乳用特征。通过将疾病记录分配到相邻的官方测试日期，创建了一个疾病数据的纵向二元结构（0=健康；1=患病）。使用逻辑回归模型分析体型特征对疾病（临床型乳腺炎和蹄病）风险的影响。
与体型特征总分较低（75-79 分）的奶牛相比，总分较高（80-85 分）的奶牛发生乳腺炎的风险显著降低（P<0.001）。泌乳奶牛临床型乳腺炎的疾病状态（0 或 1：二项变量）显著受到年龄的负面影响（P<0.05）。前乳房附着（FUA）、角度、后附着高度（RAH）和后乳区位置（RTP）均与泌乳期间的临床型乳腺炎显著相关（P<0.05）。后肢后视图（RLRV）与泌乳期间的蹄病显著相关（P<0.05）。RLRV 跛行风险维度的理想评分 4 分可能表示跛行风险较低。由于随着该特征评分的增加，乳腺炎风险降低，因此 RTP 可能是乳腺炎风险的理想标志物。
根据本研究，可使用奶牛体型特征来评估其发生临床型乳腺炎和蹄病的风险。后乳区中位于中央的奶牛发生乳腺炎的风险较低。这些结果可能有助于奶牛养殖户在泌乳早期识别高疾病风险的奶牛，并有助于奶牛的抗病性选育。
