[目的]本试验旨在研究新型补钙丸剂对奶牛产后低血钙症的防治作用。[方法]选取34 头健康2 胎次以上的经产奶牛,随机分为2组,每组17 头牛。试验组（EG组）奶牛投服新型补钙丸剂,对照组（CG组）奶牛投服常用补钙剂。在4 个时间点（产后0 h、第1次投服补钙剂后2 h、第1次投服补钙剂后12 h和第2次投服补钙剂后2~4 h）采集尾根静脉血样,测定血液矿物元素含量、血气指标、血液生化指标,并记录产后30 d内的平均产奶量和代谢性疾病发生率。[结果]结果表明,1）投服2 种补钙剂后,4 个时间点中所有奶牛产后血液离子钙（iCa）的含量均上升,且EG组两次投服补钙剂后,血钙上升幅均显著优于CG组,第一次投服后12 h EG组iCa显著高于CG组（P<0.05）。第2次投服补钙剂2~4 h后所有奶牛血液中钠离子（Na⁺）以及血液钾离子（K⁺）含量显著高于产后0 h（P<0.05）。2）EG组奶牛第1次投服补钙剂12 h后血液酸碱平衡指标显著高于CG组（P<0.05）。不同时间点血气指标对比结果显示,EG组奶牛第1次投服补钙剂12 h和第2次投服补钙剂2~4 h后,血液酸碱平衡指标、碳酸氢根（HCO₃^-）含量显著高于产后0 h和第1次投服补钙剂2 h（P<0.05）。EG组奶牛第1次投服补钙剂12 h与第2次投服补钙剂2~4 h后血液总二氧化碳（TCO₂）含量显著高于EG组产后0 h（P<0.05）。3）奶牛产后投服两种补钙剂后,EG组与CG组的血液葡萄糖（Glu）、红细胞压积（Hct）、血红蛋白（Hb）含量均呈下降趋势。且CG组在第2次投服补钙剂2~4 h后,红细胞压积（Hct）、血液葡萄糖（Glu）、血红蛋白（Hb）含量均显著低于产后0 h（P<0.05）。4）EG组奶牛平均产奶量显著高于CG组（P<0.05）,EG奶牛产后疾病发病率低于CG组。[结论]综上所述,奶牛产后投服新型补钙丸剂可快速提升血钙浓度,降低产后低血钙症发病率;与目前国内牧场常用的产后钙棒相比,其提升血钙效果更显著。该丸剂有助于维持电解质、酸碱平衡及能量代谢稳态,从而减轻产犊应激对奶牛生产性能的负面影响,为奶牛围产期低血钙管理提供了新的方案选择。

[Objective] This experiment aimed to study the preventive and therapeutic effects of the new calcium supplement pills on postpartum hypocalcemia in dairy cows. [Method] Thirty-four healthy multiparous dairy cows of more than two litters were selected and randomly divided into two groups,with 17 cows in each group. The cows in the experimental group （EG group） were given the new calcium supplement pills,while the cows in the control group （CG group） were given the commonly used calcium supplement. Tail-root venous blood samples were collected at four time points （0 hours postpartum,2 hours after the first administration of calcium supplement,12 hours after the first administration of calcium supplement,and 2~4 hours after the second administration of calcium supplement） to determine the content of blood mineral elements,blood gas indicators,and blood biochemical indicators. The average milk production and the incidence of metabolic diseases within 30 days postpartum were also recorded. [Result] The results showed that：1）After administration of two calcium supplements,the postpartum blood ionic calcium （iCa） content of all dairy cows at the four time points increased. Moreover,after the two administration of calcium supplements in the EG group,the increase in blood calcium was significantly better than that in the CG group. 12 hours after the first administration,the iCa content in the EG group was significantly higher than that in the CG group （P<0.05）. Two - four hours after the second administration of calcium supplements,the contents of sodium ions （Na⁺） and potassium ions （K⁺） in the blood of all dairy cows were significantly higher than those at 0 hours postpartum （P<0.05）. 2） The blood acid-base balance index of dairy cows in the EG group was significantly higher than that in the CG group 12 hours after the first administration of calcium supplement （P<0.05）. The comparison results of blood gas indicators at different time points showed that 12 hours after the first administration of calcium supplement and 2~4 hours after the second administration of calcium supplement in the EG group of dairy cows,the blood acid-base balance index and bicarbonate （HCO₃^-） in the blood were significantly higher than those at 0 hours after delivery and 2 hours after the first administration of calcium supplement （P<0.05）. The total carbon dioxide （TCO₂） content in the blood of dairy cows in the EG group 12 hours after the first administration of calcium supplement and 2~4 hours after the second administration of calcium supplement was significantly higher than that in the EG group 0 hours after delivery （P<0.05）. 3） After postpartum administration of two calcium supplements to dairy cows,the contents of blood glucose （Glu）,hematocrit （Hct）,and hemoglobin （Hb） in both the EG group and the CG group showed a downward trend. Moreover,in the CG group,2~4 hours after the second administration of calcium supplements,the contents of hematocrit （Hct）,blood glucose（Glu）,and hemoglobin （Hb） were significantly lower than those at 0 hours postpartum （P<0.05）. 4） The average milk production of dairy cows in the EG group was significantly higher than that in the CG group （P<0.05）,and the incidence of postpartum diseases in EG dairy cows was lower than that in the CG group. [Conclusion] To sum up,postpartum administration of the new calcium supplement pills to dairy cows can rapidly increase blood calcium concentration and reduce the incidence of postpartum hypocalcemia. Compared with the postpartum calcium rods commonly used in domestic pastures at present,its effect of increasing blood calcium is more significant. This pill helps maintain electrolyte,acid-base balance and energy metabolism homeostasis,thereby reducing the negative impact of calving stress on the production performance of dairy cows and providing a new option for the management of perinatal hypocalcemia in dairy cows.