牦牛犊牛体内矿物质元素钙、磷、钠、钾、镁沉积分布规律

Distribution Pattern of Mineral Elements Calcium,Phosphorus,Sodium,Potassium and Magnesium Deposition in Yak Calves

试验旨在探究40~90 kg牦牛犊牛体内主要常量矿物质元素分布规律。选取35头体重(46.40±6.50)kg、日龄(60±3)d、健康的牦牛公犊牛为试验动物,随机等分为5组,即起始屠宰组(BL),中期屠宰组(M),终末期屠宰的高饲喂组(自由采食,AL组)、中饲喂组(70%自由采食,IR70)和低饲喂组(40%自由采食,IR40)。试验各组犊牛按不同生长阶段饲喂一定量代乳粉,同时自由采食苜蓿干草和开食料;高饲喂组、中饲喂组和低饲喂组犊牛在同期饲喂等量代乳粉基础上,分别按自由采食、70%采食量、40%采食量补充饲喂苜蓿干草和开食料,精粗比均为3∶7。根据试验不同时间点每组随机选取5头牦牛进行屠宰采样,测定体内各组织中的主要常量矿物质含量,分析获得钙、磷、钠、钾、镁在牦牛犊牛体内沉积分布规律。结果表明:(1)内脏(含血液)、脂肪组织中的干物质含量随体重增加而增加,且AL、IR70组和IR40组均高于M组和BL组。(2)钙主要分布在骨骼(98.14%);磷也主要分布在骨骼(86.19%),在肉和内脏(含血液)中有少量分布;钠元素35.69%分布在骨骼中,18.39%分布在牛皮,17.81%分布在内脏(含血),16.22%分布在肉中,其余少量的钠分布于脂肪和毛中;钾在肉中分布量最大,为41.65%,在内脏(含血液)中的含量为36.41%,牛毛(8.21%)、牛皮(6.04%)和骨骼(5.26%)中钾含量也较为丰富,在脂肪中的含量(2.43%)较少;72.81%的镁分布在骨骼中,在肉中的含量为13.76%,在内脏(含血液)和牛毛中含量相近,剩余少量分布在牛皮和脂肪中。综上得出,牦牛犊牛体内主要常量矿物质元素沉积量随体重和饲喂量增加而增加;钙、磷、钠、镁主要分布于骨骼中,钾主要分布于肉中,在软组织和牛毛中含量也较为丰富;各主要常量矿物质元素在脂肪中分布均匀,且含量较少。

The purpose of this experiment is to explore the distribution law of major mineral elements in 40-90 kg yak calves.Thirty-five healthy yak calves with body weight of(46.40±6.50)kg and age of(60±3)d were randomly divided into five groups,namely initial slaughter group(BL group),middle slaughter group(M group),high feeding group(free feeding group,AL group),middle feeding group(70%)and low feeding group(IR40).Calves in each experimental group were fed with a certain amount of milk replacer according to different growth stages,and were free to eat alfalfa hay and open food at the same time.Calves in high feeding group,middle feeding group and low feeding group were fed with the same amount of milk replacer in the same period,and were supplemented with alfalfa hay and open food according to free intake,70% intake and 40% intake,respectively,with a concentrate-to-coarse ratio of 3∶7.According to the different time points of the experiment,five yaks were randomly selected from each group for slaughter sampling,and the main macro mineral contents in various tissues in the body were determined,and the deposition and distribution laws of calcium,phosphorus,sodium,potassium and magnesium in yak calves were obtained by analysis.The results showed that:①The dry matter content of viscera(including blood)and adipose tissue increased with the increase of body weight,and the AL group,IR70 group and IR40 group were higher than those of M group and BL group.②Calcium is mainly distributed in bones(98.14%);Phosphorus is also mainly distributed in bones(86.19%),with a small amount in meat and internal organs(including blood);35.69% of sodium is distributed in bones,18.39% in cowhide,17.81%in viscera(including blood),16.22% in meat,and the rest is distributed in fat and hair.Potassium is the most widely distributed in meat,accounting for 41.65%,and in viscera(including blood)for 36.41%.Potassium is also abundant in cow hair(8.21%),cowhide(6.04%)and bones(5.26%),and less in fat(2.43%).72.81% of magnesium is distributed in bones,and the content in meat is 13.76%,which is similar in viscera(including blood)and cow hair,and the rest is distributed in cowhide and fat.To sum up,the deposition of major mineral elements in yak calves increases with the increase of body weight and feeding amount;Calcium,phosphorus,sodium and magnesium are mainly distributed in bones,potassium is mainly distributed in meat,and it is also rich in soft tissues and cow hair.The major mineral elements are evenly distributed in the fat,and the content is small.