围产期奶牛血钙影响因素及其与生产性能关系分析

本试验旨在探究围产期奶牛血钙浓度影响因素及其与生产性能的关系。于2018年7月20日—8月15日对北京地区36头围产期健康荷斯坦牛的血钙浓度进行测定,收集该牛场奶牛生产性能测定(DHI)报告,利用固定效应模型分析不同胎次、体况评分(BCS)、健康状况及血钙浓度变异度对血钙浓度的影响。结果表明:血钙浓度与产后天数存在显著的正向相关关系;经产牛的血钙浓度(1.40 mmol/L)极显著高于初产牛(1.31 mmol/L);不同BCS分组奶牛血钙浓度差异不显著;健康组的血钙浓度(1.41 mmol/L)显著高于患病组(1.30 mmol/L);血钙浓度变异度的大小影响奶牛的产奶量,初产奶牛低变异度组的产奶量(16.70 kg/d)显著高于中变异度组(9.75 kg/d)和高变异度组(5.63 kg/d)。本研究进一步揭示了围产期荷斯坦牛血钙浓度的变化规律以及其影响因素,为预防奶牛产后低血钙症的发生以及制定提高奶牛生产性能的饲养管理策略提供参考。

Study on Factors Affecting Perinatal Dairy Cows' Blood Calcium and Its Relationship with Milk Yield

This study was designed to measure perinatal dairy cows' blood calcium and to explore how the factors affect it and the relationship with milk yield. Dairy cows' blood calcium was measured from 36 perinatal healthy Holstein cattle in Beijing area from July 20th to August 15th, 2018, and DHI data of researched dairy farms was collected. The effects of parity, BCS, health conditions and blood calcium concentration variability were analyzed using a fixed model. The result showed that there was a significant positive correlation between blood calcium concentration and postpartum days. The blood calcium concentration of multiparous cows(1.40 mmol/L) was extremely significant higher than that of primiparous cows(1.31 mmol/L). There was no significant difference in blood calcium concentration between cows in different BCS groups. The healthy group(1.41 mmol/L) was significantly higher than the sick group(1.30 mmol/L). The variability of blood calcium concentration had an effect on milk yield. The milk yield of low variability group of primiparous cows(16.70 kg/d) was significantly higher than that of medium variability group(9.75 kg/d) and high variability group(5.63 kg/d). This study intensively illustrates the factors affecting blood calcium during perinatal period and explores the impacts of blood calcium concentration variability on the milk yield in Holstein population, which could provide a scientific basis for improving the management efficiency of dairy cows.