酮病是高产奶牛常发的代谢性疾病，本试验旨在通过分析奶牛泌乳早期的生产性能DHI(奶牛群体改良)以及外周血的血细胞成分分析数据，阐明酮病发生与以上指标的相关性，及早预警牧场牛群酮病的发展。[方法]连续3年(2018—2020年)追踪江苏省境内某规模化牧场高产奶牛产后前3个月酮病高发期的生产性能数据，筛选出25头健康和20头酮病奶牛，进一步采集2020年产后第1个月的外周血进行血细胞分析; 通过二元Logistic回归模型分析各指标对酮病的预警作用，通过受试者工作特征(ROC)分析确定各指标对酮病的预警值。[结果]奶牛生产性能的回归分析结果显示:乳脂率与酮病显著正相关，乳糖率与酮病显著负相关; 奶牛血细胞成分分析结果表明:淋巴细胞数和嗜酸性粒细胞数是与酮病正相关的指标; 进一步相关分析发现:鲜牛乳中乳脂率和血液中淋巴细胞数两项联合指标对奶牛酮病具有显著的预警作用，其中乳脂率的最佳分界值为4.21%，淋巴细胞数的最佳分界值为4.815×109 L-1。[结论]生鲜奶中的乳脂率和外周血中的淋巴细胞数可作为奶牛产后发生酮病的预警依据，用于指导牧场及时做好调控管理。
Ketosis is a common metabolic disease found in high-yielding dairy cows. This study aimed to clarify the correlation between ketosis occurrence and the follow indicators by analyzing the data of dairy herd improvement(DHI)and the peripheral blood cell component. [Methods]The cow's production performance data of high-incidence period of ketosis at the first 3 months postpartum were tracked in a large-scale pasture in Jiangsu Province for 3 consecutive years(2018-2020),and 25 healthy and 20 ketotic cows were screened. The peripheral blood of the 45 cows at the first month postpartum in 2020 was selected for further blood cell analysis. The warning effect of each index on ketosis was determined by binary Logistic regression model analysis. And the warning value of each index on ketosis was determined by receiver operating characteristic(ROC)analysis. [Results]The results of dairy herd improvement showed that the milk fat rate had a direct positive relationship with ketosis,and the lactose rate was significantly negatively associated with ketosis. Blood cell analysis of dairy cows showed that the number of lymphocytes and eosinophils were indicators significantly positively associated with ketosis. Further correlation analysis showed that the milk fat rate and the number of lymphocytes had an early warning effect on ketosis. The optimal threshold value of milk fat rate was 4.21% and the optimal threshold value of the number of lymphocytes was 4.815×109 L-1. [Conclusions]The milk fat rate in milk and the number of lymphocytes count can be used as the warning indexes for ketosis in postpartum cows,and can be used to guide the timely regulation and management of dairy farms.
作者简介:华加敏，硕士研究生。 *通信作者:蔡亚非，教授，博导，主要从事牛遗传育种研究，E-mail:ycai@njau.edu.cn。