低蛋白质日粮对育肥绵羊生长性能、胴体性状及肌肉脂肪酸组成的影响

本研究旨在研究降低全混合日粮蛋白质水平对育肥期绵羊生长性能、胴体性状及肌肉脂肪酸组成的影响.试验将32只平均体重为(38.14±0.45)kg的育肥期绵羊随机分为2组,每组8个重复,每个重复2头.两组绵羊在为期10周的试验期中分别饲喂蛋白质水平为13.5％和8.5％的全混合日粮.结果:将全混合日粮蛋白质水平从13.5％...

Effects of low protein diet on growth performance,carcass traits and muscle fatty acid composition of fattening sheep

The purpose of this study was to study the effects of reducing the protein level of total mixed diet on the growth performance,carcass traits and muscle fatty acid composition of sheep in fattening period.Thirty-two sheep with an average body weight of 38.14±0.45 kg were randomly divided into 2 groups with 8 replicates per group and 2 sheep per replicate.Two groups of sheep were fed a total mixed diet containing 13.5%and 8.5%protein,respectively,during a 10-week trial.Results:The final weight,weight gain,daily gain and daily feed intake of sheep in control group were significantly increased by 8.07%,19.82%,19.82%and 10.07%(P<0.05)when the protein level of total mixed diet was reduced from 13.5%to 8.5%(P<0.05).However,there was no significant difference between control group and low protein group on feed/gain(P>0.05).The slaughter percentage and relative fat weight of sheep in control group were significantly increased by 9.80%and 19.93%in low protein group(P<0.05),respectively,but there was no significant difference in the relative weight of other tissues and organs(P>0.05).However,the L and B values of meat color and the ratio of muscle N-6 to N-3 fatty acids were significantly decreased by 8.64%,7.27%and 20.74%(P<0.05).Conclusions:Although reducing protein levels in total mixed diets from 13.5%to 8.5%in fattening sheep has negative effects on body weight,feed intake,daily gain and slaughter rate,feed efficiency and muscle fatty acid composition are not affected,and drop loss and the ratio of N-6 to N-3 fatty acids are significantly improved.