不同泌乳阶段奶牛血清矿物元素含量的变化

The changes of serum mineral element content of dairy cows at different lactation stages

试验旨在探讨不同泌乳阶段和产奶量对奶牛血清矿物元素含量的影响。试验采用2×5(产奶量:高产≥35 kg/d和低产<35 kg/d;泌乳阶段:围产前期、围产后期、泌乳前期、泌乳中期和泌乳后期)二因素完全随机试验设计,选择40头荷斯坦奶牛,分析产奶量与泌乳阶段对血清常量元素(钙、磷、钾、镁)与微量元素(镉、钴、铬、钼、铅、铜、锰、硒、铁、锌)含量的影响。结果表明产奶量对血清矿物元素含量无显著影响(P>0.05),泌乳阶段对血清矿物元素含量影响显著(P<0.05)。除泌乳后期外,其它阶段血清铜含量均较低,接近阈值;泌乳前期和围产后期血清硒及围产后期钴含量较低,且低于正常范围;各阶段血清铁含量均较低;泌乳后期铅含量高于正常范围;其它各阶段其余元素含量均在正常范围内。因此,生产中应针对不同生理阶段注意元素铁、硒、铜、钴的及时供给,并预防泌乳后期铅中毒。

The aim of this study was to investigate the effects of different lactation stages and milk pro- duction on serum mineral elements in dairy cows. The experiment was conducted as a 2 × 5 （milk pro- duction： high, ≥ 35 kg/d or low, 〈35 kg/d; lactation stage： prepartum, postpartum, early-lactation, mid- lactation and late-lactation） factorial arrangement. Forty Holstein dairy cows were selected. The effects of milk kalium and lactation stage on the concentrations of macro-element including calcium, phospho- rus, kalium and magnesium, and micro-element such as cadmium, cobalt, chromium, molybdenum, plumbum, copper, manganese, selenium, iron and zinc in serum were analyzed. The results showed that the milk production had no significant effect on serum mineral content of dairy cows （P〉0.05）, while the effect of lactation stage on serum mineral content was significant （P〈0.05）. In addition to late-lactation, other stages of serum copper levels were low, close to the threshold. Early-lactation and postpartum of serum selenium and postpartum of serum cobalt content were low, and lower than the normal range. Serum iron level was low at all stages. The serum plumbum content at late-lactation stage was higher than the normal range. And other stages of the remaining elements were in the nor- real range. Therefore, the element iron, selenium, copper, cobalt should be timely supplied at different physiological stages in the production, and prevent plumbum poisoning at late-lactation stage.