饲粮添加氨基酸锌对育肥羊屠宰性能、肉品质及血液和组织中微量元素含量的影响

本试验旨在研究氨基酸锌对育肥羊屠宰性能、肉品质及血液和组织中微量元素含量的影响。选择4月龄、体重为(29.00±0.61)kg的健康滩湖杂F1代公羊48只,随机分为4组,每组12只。对照组饲粮锌含量为52.80 mg/kg(硫酸锌),其中不含硫酸锌的锌含量为18.02 mg/kg,试验Ⅰ组、试验Ⅱ组、试验Ⅲ组试验饲粮锌含量分别为对照组饲粮的1/2、1和2倍(氨基酸锌),预试期7 d,正试期60 d。结果表明:饲粮添加氨基酸锌显著提高了育肥羊平均日增重(P<0.05),以试验Ⅱ组平均日增重最高,达到283.59 g/d。饲粮添加氨基酸锌对育肥羊屠宰性能、肉质理化性状无显著影响(P>0.05),但随着饲粮氨基酸锌添加量增加,试验组肉骨比、背膘厚、眼肌面积先升高后降低,GR值、肌内脂肪含量升高,剪切力降低;试验组血液锌含量均高于对照组,在同等锌添加量条件下,试验Ⅱ组血清锌含量极显著高于对照组(P<0.01);各组间背最长肌、肾脏、心脏、肝脏及肺脏组织的锌含量差异不显著(P>0.05),但氨基酸锌添加量过高会影响肌肉、肾脏、心脏、肺脏中铁沉积及肝脏中铜沉积。综上所述,饲粮添加氨基酸锌可促进育肥羊生长,改善肉品质;在锌含量为18.02 mg/kg的基础饲粮中添加52.80 mg/kg锌(氨基酸锌)效果最佳。

Effects of Adding Amino Acid Zinc in Diets on Slaughter Performance,Meat Quality and Trace Element Contents in Blood and Tissue of Fattening Sheep

This experiment was conducted to investigate the effects of adding amino acid zinc in diets on slaughter performance,meat quality and trace element contents in blood and tissue of fattening sheep.Forty-eight ram Tan×Hu sheep at 4 months of age,which had a good condition and(29.00±0.61)kg body weight,were randomly divided into 4 groups,and 12 sheep in each group.Zinc content of the control group diet was 52.80 mg/kg(sulfate zinc).Zinc content of the test groupⅠ,test groupⅡand test groupⅢwas 1/2,1 and 2 times(amino acid zinc)of the control group diet,respectively.Pretrial period was 10 d,and trial period was 60 d.The results showed as follows:adding amino acid zinc to diets significantly increased the average daily gain of fattening sheep(P<0.05),and the average daily gain of groupⅡwas 283.59 g/d;there was no significant effect on slaughter performance and meat physicochemical properties of fattening sheep.However,with the increase of dietary amino acid zinc content,the meat to bone ratio,backfat and eye area of the test groups increased first and then decreased,the GR value and the content of fat in muscle increased,and the shear of tenderness decreased;the content of zinc in the blood in test groups was higher than that in control group,and in the test group,and under the same amount of zinc added condition,the content of zinc in test groupⅡwas significantly higher than that in control group(P<0.01);zinc deposition in the longissimus dorsi,kidney,heart,liver and lung among the groups was not significant(P>0.05),however,too much amino acid could affect the deposition of iron in muscle,kidney,zinc,lung and copper in liver.It is concluded that dietary addition of amino acid zinc can promote the growth of fattening sheep,improve meat quality,with the 18.02 mg/kg of basal diet zinc content,effect of zinc addition with 52.80 mg/kg(amino acid zinc)is the best.