饲粮阴阳离子差对围产期奶牛血清生理生化指标及犊牛血清抗氧化指标的影响

Effects of Dietary Cation-Anion Difference on Physiological and Biochemical Indexes in Serum of Peripartum Dairy Cows and Anti-Oxidant Indexes in Serum of Calves

本试验旨在研究围产前期饲粮阴阳离子差(DCAD)对产后奶牛血清生理生化指标及犊牛血清抗氧化指标的影响。试验采取单因子随机区组试验设计,选取2~4胎次、体重相近、预产期相近的围产前期(产前28天)中国荷斯坦奶牛20头,分为4组,每组5头。4组分别在围产前期饲喂DCAD为+262.31、+130.26、+78.51、+6.67 mmol/kg(干物质基础)的饲粮,阴离子盐的添加量分别为0、15.0、21.9、29.1 g/kg。试验期49 d,其中预试期7 d,正试期42 d。结果表明:降低奶牛产前饲粮DCAD能显著提高其血清钙含量(P<0.05);显著降低尿液p H(P<0.05);显著提高产后血清维生素D含量(P<0.05);显著提高犊牛血清抗氧化能力(P<0.05);但对奶牛血清肿瘤坏死因子、甲状旁腺素、降钙素和β-羟丁酸含量没有显著影响(P>0.05)。因此,添加阴离子盐降低产前奶牛饲粮的DCAD可以促进其血清钙稳态,诱发机体轻度代谢性碱中毒从而减少产褥热的发病率,并提高犊牛的抗氧化能力。本试验条件下,15.0 g/kg(干物质基础)为阴离子盐最佳添加量。

This experiment was conducted to evaluate the effects of dietary cation-anion difference （DCAD ） on physiological and biochemical indexes in serum of peripartum dairy cows and anti-oxidant indexes in serum of calves. The test was adopted using single factor randomized block design. Twenty 2 to 4 parities Chinese Holstein antepartum cows （28 d ） with similar body weight and expected date of confinement were allocated in-to 4 groups with 5 cows per group. Cows were fed 4 experimental diets with DCAD at ＋262.31, ＋130.26, ＋78.51 and ＋6.67 mmol/kg （ dry matter basis）, respectively, and the supplemental level of anionic salt was 0, 15.0, 21.9 and 29.1 g/kg , respectively. The experiment lasted for 49 days with the first 7 days as adapta-tion period and the following 42 d as trial period. The results showed that reducing dietary DCAD of antepartum period could significantly improve serum calcium content （P 〈0.05） , significantly decrease urine pH （P 〈 0.05） , and significantly improve postpartum serum vitamin D content of dairy cows （P 〈0.05） , as well as significantly decrease serum malondialdehyde content of calves （P〈0.05） ; however, there were no significant effects on serum tumor necrosis factor a , parathyroid hormone, calcitonin and beta hydroxybutyrate contents a-mong 4 groups （P〉0.05）. Therefore, the results indicate that anionic salts supplementation in diet for antepar-tum cows can promote the serum calcium homeostasis, induce mild metabolic acidosis, so as to reduce the inci-dence of puerperal fever in cows, and improve anti-oxidant ability of their calves.