Lactation and Immuno-Physiology Laboratory, ICAR-National Dairy Research Institute, Karnal, Haryana, 132001, India; Animal Production Division, Agricultural College, Aleppo University, Aleppo, Syrian Arab Republic.
Livestock Production & Management Section, ICAR-National Dairy Research Institute, Karnal, Haryana, 132001, India.
J Trace Elem Med Biol. 2021 May;65:126718. doi: 10.1016/j.jtemb.2021.126718. Epub 2021 Jan 14.
Periparturient period induces stress in cows which fluctuates hormonal and metabolic function and causes immune suppression. Apart from impairing the health, production, and reproduction of cows, it also influences the well-being of newborn calves by decreasing the colostrum quality. Micronutrients are known for optimal health and production and their effects on parturition stress, immune response in both cow and its calf need to be explored.
The aim of this study was to see the effect of oral supplementation of micronutrients during the prepartum period on the health status of crossbred dairy cows and subsequently on their newborn calves.
A total of 42 healthy multiparous cows were selected and randomly divided into five groups with seven cows in each group, i.e. control (Basal Diet, BD), VA group (BD + vitamin A, 10 IU), Zn group (BD + zinc sulphate, 60 ppm), VE group (BD + vitamin E, 2500 IU), and combined supplementation (CS) group (BD + combination of VA, Zn, and VE). The supplements were offered in compounded concentrate DM (100 g) to individual cows once daily before the morning feeding and the remaining portion was incorporated in the TMR. Feeding was started one month before the expected days of calving till calving. Blood samples were collected from cows at days -15, -7, -3, 0, +3, +7, and +15 relative to the day of calving. Blood samples from newborn calves and milk samples of cows were collected at days 0, +3, +7, and +15. Milk somatic cell counts (SCC) were estimated using a cell counter. Cortisol was estimated by ELISA kit in blood and milk plasma of cows and in the blood plasma of their calves. Total immunoglobulins (Ig) were estimated in milk of cows and serum of calves using zinc sulphate turbidity method. Blood neutrophils from cows and calves were studied for phagocytic activity (PA) using nitro blue tetrazolium (NBT) assay.Data were analysed by repeated-measures two-way ANOVA using the mixed procedure of SAS, and the pairwise comparison was performed using a multiple comparison test (Tukey).
Combined supplementation of micronutrients decreased (P < 0.05) maternal blood plasma (control vs. CS group, 5.98 ± 0.20 vs. 3.86 ± 0.23 ng/mL) and milk plasma (3.96 ± 0.13 vs. 2.71 ± 0.10 ng/mL) cortisol, milk SCC (3.05 ± 0.11 vs. 2.12 ± 0.10 × 10 cells/mL) and increased (P < 0.05) total milk Ig concentration (18.80 ± 0.11 vs. 23.04 ± 0.57 mg/mL) and the PA of blood neutrophils (0.84 ± 0.03 vs. 1.07 ± 0.03). Similarly, lower blood cortisol concentration (9.69 ± 0.35 vs. 6.02 ± 0.18 ng/mL) and higher (P < 0.05) total Ig (23.26 ± 0.11 vs. 30.34 ± 0.70 mg/mL) and PA of blood neutrophils (0.37 ± 0.02 vs. 0.52 ± 0.02) were observed in the calves born to CS group of cows as compared to the control. Highest (P < 0.05) positive effects (lower stress levels and higher immune response) of treatment were noticed in CS group followed by VE group and then Zn group. However, VA group didn't differ from the control group.
Our results indicate that micronutrient interventions during the prepartum period can improve the health status of dairy calves and subsequently the well-being of their calves.
围产期会给奶牛带来应激，使它们的激素和代谢功能发生波动，导致免疫抑制。除了损害奶牛的健康、生产和繁殖外，还会通过降低初乳质量来影响新生牛犊的健康。微量元素对最佳健康和生产至关重要，但其对奶牛及其牛犊分娩应激和免疫反应的影响需要进一步研究。
本研究旨在观察围产期口服补充微量元素对杂交奶牛健康状况的影响，进而对其新生牛犊产生影响。
选择 42 头健康的经产奶牛，随机分为五组，每组 7 头，分别为对照组（基础日粮，BD）、VA 组（BD+维生素 A，10IU）、Zn 组（BD+硫酸锌，60ppm）、VE 组（BD+维生素 E，2500IU）和联合补充组（CS）（BD+VA、Zn 和 VE 的组合）。每天在早上喂食前，将补充剂以 100g 复合浓缩 DM 的形式提供给个体奶牛，其余部分添加到 TMR 中。从预计分娩前一个月开始喂养，直到分娩。从分娩前 15 天、-7 天、-3 天、0 天、+3 天、+7 天和+15 天收集奶牛的血液样本。从新生牛犊和奶牛的牛奶样本中收集第 0、+3、+7 和+15 天的样本。使用细胞计数器估计牛奶体细胞计数（SCC）。使用 ELISA 试剂盒在奶牛的血液和牛奶血浆以及其牛犊的血液血浆中估计皮质醇。使用硫酸锌浊度法在奶牛的牛奶和牛犊的血清中估计总免疫球蛋白（Ig）。使用硝基蓝四唑（NBT）测定法研究奶牛和牛犊的血液中性粒细胞的吞噬活性（PA）。使用 SAS 的混合程序分析重复测量的两因素方差，并使用多重比较检验（Tukey）进行成对比较。
联合补充微量元素降低了（P<0.05）母体血液血浆（对照组与 CS 组相比，5.98±0.20 vs. 3.86±0.23ng/mL）和牛奶血浆（3.96±0.13 vs. 2.71±0.10ng/mL）皮质醇、牛奶 SCC（3.05±0.11 vs. 2.12±0.10×10 细胞/mL），并增加了（P<0.05）牛奶总 Ig 浓度（18.80±0.11 vs. 23.04±0.57mg/mL）和血液中性粒细胞的 PA（0.84±0.03 vs. 1.07±0.03）。类似地，CS 组牛犊的血液皮质醇浓度较低（9.69±0.35 vs. 6.02±0.18ng/mL），总 Ig 较高（23.26±0.11 vs. 30.34±0.70mg/mL），血液中性粒细胞的 PA 较高（0.37±0.02 vs. 0.52±0.02）。与对照组相比，CS 组牛犊的总 Ig 和 PA 也具有更高的正效应（更低的应激水平和更高的免疫反应）。
我们的研究结果表明，围产期补充微量元素可以改善奶牛的健康状况，进而提高其牛犊的健康水平。
