不同气温对奶牛体内几种微量元素代谢影响的研究

Study on the Influence of Different Temperature to Some Trace Element Metabolism in Cows

选择5头体重相近,体质外貌相似,生产性能相近,日产奶量为15 kg左右的健康 牛。在气温为10℃以下、10-20℃、20-30℃、30-40℃左右维持15 d,分别采取试验牛的血、 乳和毛样,经消化处理后,研究不同气温对其影响情况,结果表明,气温达20℃以上,牛血液中 Zn含量开始下降,当气温达30-40℃,牛全血中Zn含量最低(P<0．01),Fe浓度明显下降(P <0．05),Cr含量急剧减少(P<0．011),Cu、Mn、Co的含量增加、Se含量有减少,但差异不显著 (P>0．05)。环境温度升高可明显增加乳中Zn、Fe含量(P<0．01),同时,Se、Cr、Mn含量也增 加,Co的含量减少(P<0．05),Cu含量变化无规律。环境温度对毛中Zn、Fe、Cu无规律性影 响,但环境温度升高,Se、Mn含量增加,Cr、Co含量减少(P<0．05)。

Five healthy cows with 15 kg milk yields per day were selected, which had similar weight, constitution and appearance. The cows had been keeping under 10℃, 10-20℃, 20-30℃, and 30-40℃ for 15 days, Then the blood, milk and hair of the cows were adopted and treatmented respectively. The influence of different temperature to trace elements in the cow＇s blood ,milk and hair samples were studied. The results showed that when the cow shed temperature was up to more than 20℃, Zn content in cow＇s blood began tO drop, and was minimum when the temperature was 30-40℃ （P〈0. 01）. Meanwhile, Fe and Cr contents in cow＇s blood reduced obviously （P〈0. 01）, Se content in cow＇s blood reduced too （P〉 0.05）, but the Cu, Mn, Co contents in cow＇s blood increased. When the temperature was up, the Fe, Zn, Se, Cr, Mn Contents in cow＇s milk were increased at different degree, but the Co content reduced obviously （P〈0. 05）, and the Cu content in milk of cows changed irregularly. Correspandly, The Se, Mn contents in cow＇s hairs increased, and the Cr, Co contents in cow＇s hairs reduced when the temperature was up, but the Zn; Fe, Cu contents in the same samples changed irregularly.