Veterinary Medicine Teaching and Research Center, 18830 Road 112, Tulare, CA 93274.
INRA, Université Clermont Auvergne, VetAgro Sup, UMR Herbivores, F-63122 Saint-Genès-Champanelle, France.
J Dairy Sci. 2018 May;101(5):4460-4472. doi: 10.3168/jds.2017-12917. Epub 2018 Mar 1.
The effects of prophylactic oral Ca supplementation on blood mineral status and markers of energy balance were evaluated on 205 multiparous Jersey cows at a commercial dairy. Postpartum, cows were systematically assigned to control (n = 105) or oral Ca supplementation (CaOS; 50 to 60 g of Ca as boluses; n = 100) at 0 and 1 d in milk (DIM). Blood samples for analysis of serum minerals (Ca, P, Mg, K, Na, Fe, Zn, and Cu) were collected before and 1 h after treatment at 0 and 1 DIM, and at 2 DIM. Urine pH was measured immediately before and 1 h after treatment administration (n = 96). A subset of 74 cows was evaluated for plasma glucose and fatty acid concentrations at 0, 1, and 2 DIM. Cows were classified according to their initial calcemic status (Ca status) as normocalcemic (NC; serum Ca >2.12 mmol/L) or subclinically hypocalcemic (SCH; serum Ca ≤2.12 mmol/L). Average serum Ca concentration was higher in CaOS than control cows (2.12 vs. 2.06 mmol/L); this treatment effect was higher for SCH [CaOS (2.03 mmol/L); control (1.89 mmol/L)] than NC cows [CaOS (2.22 mmol/L); control (2.22 mmol/L)]. The incidence of subclinical hypocalcemia was lower for CaOS than control cows (53 vs. 65%); however, at 2 DIM the prevalence of subclinical hypocalcemia tended to be higher for CaOS cows, mostly because it was higher for CaOS-NC than control-NC cows (70 vs. 25%). Urine pH was lower for CaOS than control cows (6.10 vs. 7.04). Lower serum Mg concentration was detected for CaOS-SCH (1.06 mmol/L) than for control-SCH (1.10 mmol/L) cows. Cows in the CaOS group had higher serum K (4.68 vs. 4.53 mmol/L), lower plasma glucose (2.97 vs. 3.10 mmol/L), and at 2 DIM higher plasma fatty acid concentrations (0.43 vs. 0.35 mmol/L) than control cows. Our results showed that postpartum serum Ca concentration increases with oral Ca supplementation, but calcemic status influenced treatment response. Future studies should evaluate the long-term implications on production and reproduction of oral Ca supplementation in Jersey cows.
我们在一家商业奶牛场评估了预防性口服补钙对血液矿物质状况和能量平衡标志物的影响，共有 205 头荷斯坦奶牛参与该研究。产后，奶牛在第 0 天和第 1 天（D）按系统分配到对照组（n=105）或口服钙补充剂组（CaOS；50-60g 钙丸；n=100）。在第 0 天和第 1 天（D）、第 2 天（D），在治疗前和治疗后 1 小时，采集血液样本以分析血清矿物质（钙、磷、镁、钾、钠、铁、锌和铜），并在治疗前和治疗后 1 小时（n=96）测量尿液 pH 值。对 74 头奶牛的血浆葡萄糖和脂肪酸浓度在第 0 天、第 1 天和第 2 天（D）进行评估。根据初始血钙状况（钙状态），将奶牛分为正常血钙（NC；血清钙>2.12mmol/L）或亚临床低钙血症（SCH；血清钙≤2.12mmol/L）。与对照组相比，CaOS 组的平均血清钙浓度更高（2.12 对 2.06mmol/L）；SCH 组的治疗效果更高[CaOS（2.03mmol/L）；对照组（1.89mmol/L）]而 NC 组的治疗效果更低[CaOS（2.22mmol/L）；对照组（2.22mmol/L）]。与对照组相比，CaOS 组亚临床低钙血症的发生率更低（53 对 65%）；然而，在第 2 天（D），CaOS 组的亚临床低钙血症的患病率倾向于更高，主要是因为 CaOS-NC 组比对照组-NC 组更高（70 对 25%）。与对照组相比，CaOS 组的尿液 pH 值更低（6.10 对 7.04）。与对照组的 SCH 组（1.10mmol/L）相比，CaOS-SCH 组的血清镁浓度更低（1.06mmol/L）。与对照组相比，CaOS 组的血清钾（4.68 对 4.53mmol/L）更高，血浆葡萄糖（2.97 对 3.10mmol/L）更低，第 2 天（D）的血浆脂肪酸浓度更高（0.43 对 0.35mmol/L）。我们的研究结果表明，产后血清钙浓度随口服补钙而增加，但钙状态影响治疗反应。未来的研究应评估口服补钙对荷斯坦奶牛生产和繁殖的长期影响。
