PDF(Pubmed)
Abstract：
Postpartum blood calcium (Ca) concentration is related to the reproduction and health of cattle. Oral calcium supplements were given to dairy cows after calving to increase blood Ca concentration and reduce the risk of hypocalcemia. However, studies have shown that oral Ca has different effects in preventing disease. The purposes of this study were (i) to conduct a meta-analysis to evaluate the expected effect of oral Ca on incidence of calving-related diseases, pregnancy risk and milk yield in dairy cows, and (ii) to make a quality assessment of these related studies. In total, 22 eligible studies were included in this review. Meta-analysis showed that oral Ca could significantly reduce the incidence of hypocalcemia (clinical hypocalcemia: relative risk (RR) = 0.67, 95% confidence interval (CI) = [0.52, 0.87]; subclinical hypocalcemia: RR = 0.81, CI = [0.72, 0.91]), and incidence of retained placenta (RR = 0.77, CI = [0.62, 0.95]), improved blood Ca concentrations: mean difference (MD) = 0.08; 95% CI = [0.04, 0.11]. For other results, the meta-analysis revealed a lack of evidence of the correlation between oral Ca and serum magnesium (Mg) / phosphorus (P) concentration (Mg: MD = -0.04; 95% CI = [-0.10, 0.02]; P: MD = 0.05; 95% CI = [-0.10, 0.21]) or incidence of other calving-related disorders (metritis: RR = 1.06, CI = [0.94, 1.19]; ketosis: RR = 1.04, CI = [0.91, 1.18]; mastitis: RR = 1.02, CI = [0.86, 1.21]; displacement of the abomasum: RR = 0.81, CI = [0.57, 1.16]) or pregnancy risk (pregnancy risk at first service: RR = 0.99, CI = [0.94, 1.05]; overall pregnancy rate: RR = 1.03, CI = [0.98, 1.08]) or milk yield (MD = 0.44; 95% CI = [-0.24, 1.13]). The distribution of the funnel plot formed by the included studies was symmetrical, and the Egger\'s test had a p > 0.05, indicating that there was no significant publication bias. Sensitivity analyses results suggested that the results of meta-analysis are robust. Quality assessment of the included studies revealed that the risk of bias was focused on selection bias, performance bias, detection bias and other sources of bias, and the future research should focus on these aspects.
摘要：
产后血钙（Ca）浓度与牛的繁殖和健康有关。在产牛后给予奶牛口服钙补充剂，以增加血液中的Ca浓度并降低低钙血症的风险。然而,研究表明，口服钙在预防疾病方面有不同的作用。这项研究的目的是（i）进行荟萃分析，以评估口服钙对产卵相关疾病发生率的预期影响，奶牛的怀孕风险和产奶量，（ii）对这些相关研究进行质量评估。总的来说,22项符合条件的研究纳入本综述。Meta分析显示口服钙可显著降低低钙血症的发生率(临床低钙血症:相对危险度(RR)=0.67,95%置信区间(CI)=[0.52,0.87];亚临床低钙血症:RR=0.81,CI=[0.72,0.91]),和胎盘滞留发生率（RR=0.77，CI=[0.62，0.95]），改善血液Ca浓度：平均差（MD）=0.08；95％CI=[0.04，0.11]。对于其他结果，荟萃分析显示，口服钙与血清镁（Mg）/磷（P）浓度之间缺乏相关性的证据（Mg：MD=-0.04；95％CI=[-0.10，0.02]；P：MD=0.05；95％CI=[-0.10，0.21]）或其他产牛相关疾病的发生率（meta：RR=1.06，RR=[0.94，1.19]1.19=1.18时的死亡率：[=1.91纳入研究形成的漏斗图的分布是对称的，Egger检验的p>0.05，表明没有明显的发表偏倚。敏感性分析结果表明，荟萃分析的结果是稳健的。对纳入研究的质量评估表明，偏倚的风险集中在选择偏倚上，性能偏差，检测偏差和其他偏差源，未来的研究应该集中在这些方面。
