育肥牛微量元素营养状况的评价研究

Evaluation on Nutrient Status of Trace Elements in Finishing Beef Cattle

饲料中碘和铜的含量低于NRC(1996)肉牛标准,育肥牛血液中血浆蛋白结合碘(PBI)和红细胞超氧化物歧化酶(ESOD)活性、血浆铜和血清铜、毛发铜低于正常水平,添加补充料后有所改善,部分指标差异显著(P<005)。饲料中铜和碘的供给量与日增重存在显著相关(P<005)。对照组育肥牛日粮锰和锌的平均含量已达NRC(1996)标准,但部分牛仍然不足,添加补充料后血浆锌和锰的浓度有提高的趋势。饲料中锰与日增重(r=04802)、血浆锰(r=03744)的相关不显著,但血浆锰与日增重存在显著相关(r=08143,P<001)。土壤中铁和钴的含量较高,饲料中铁和钴的含量分别为NRC需要量的12倍和10倍。所有牛血液和毛发钴的含量高于钴的临界缺乏水平,但对照组部分牛的血浆铁和血红蛋白(Hb)低于正常水平,补加补充料后血红蛋白(Hb)有所提高,血浆铁明显增加(P<005)。饲料铁与血液中的铁浓度和日增重相关性较差;饲料钴与日增重没有明显相关。

An experiment was carried out to examine the performance of finishing Yunnan Yellow cattle and its crosses with Simmental or Angus fed crop residues ad libitum and 1 0kg corn meal(basal diet),with or without urea mineral and protein supplement,and to evaluate the status of trace element in beef nitrition,combined with the analysis of trace element in soil,plasma,serum,hair and biochemical index of beef.The results were as follows:(1)the concentration of iodine(I)and copper(Cu)in diet was below normal level of nutrition requirments of beef cattle of NRC(1996),and plasma binging iodine(PBI),erythrocyte superoxide dismutase(ESOD)and copper in plasma,hair and serum were significiantly increased(P<0 05)when they fed with the basal diet supplemented with urea mineral mixes.(2)the concentration of zinc(Zn)and manganese(Mn)in the basal diet mostly reached the nutrition requirments of beef cattle of NRC(1996),but some was lower than the standards.After supplementing,plasma concentrations of zinc(Zn)and manganese(Mn)increased.There was a correlation between manganese(Mn)in the plas ma and average daily gain(ADG).(3)The content of iron and cobalt(Co)in diet was 12 or 10 times of NRC(1996)respectively.Cobalt(Co)in blood and hair was above marginal level,Fe in plasma and hemoglobin (Hb)of the control was lower than the normal level,and Hb and Fe in plasma of the trail was increased.The ADG significiantiy increased from 457 g/d in the cattle fed the basal diet to 662 g/d in the cattle fed basal diet with urea mineral supplement and 893 g/d in the cattle fed basal diet with urea mineral and protein supplements,and dry matter intake(DMI)increased from 5 3 to 7 0 and 7 8 kg/d,respectively.