不同能量和蛋白质水平饲粮对宁乡猪生长性能、胴体品质和肉品质的影响

本试验旨在研究不同能量和蛋白质水平饲粮对宁乡猪生长性能、胴体品质及肉品质的影响。选用体重约18 kg的宁乡猪仔猪72头,随机分为3组(每组4个重复,每个重复6头):对照组饲喂基础饲粮(前、中、后3期蛋白质水平分别为14.03%、12.06%、11.01%;全期消化能为12.15 MJ/kg);试验A组饲喂在基础饲粮的基础上3期蛋白质水平各降低约2个百分点、全期消化能降低1.25 MJ/kg的低营养水平饲粮;试验B组饲喂在基础饲粮的基础上3期蛋白质水平各降低约3个百分点、全期消化能降低2.50 MJ/kg的超低营养水平饲粮。试验期180 d。结果表明:1)试验组前期料重比和平均日增重较对照组显著提高(P<0.05);从全期来看,3个组间生长性能差异不显著(P>0.05)。2)试验B组的肥肉率较对照组和试验A组显著降低(P<0.05),瘦肉率有提高趋势。与对照组相比,试验组胴体垂直长均极显著提高(P<0.01);试验B组胴体斜长、皮厚显著提高(P<0.05)。3)试验组背最长肌pH 1 h显著降低(P<0.05),其他肉品质性状各组间差异不显著(P>0.05)。由此可见,降低饲粮能量和蛋白质水平,对宁乡猪生长性能和肉品质没有明显负面影响,且能提高屠宰性能,改善胴体组成。在本试验中,超低营养水平饲粮对胴体组成的改善效果优于低营养水平饲粮。

Effects of Diets with Different Energy and Protein Levels on Growth Performance,Carcass Traits and Meat Quality of Ningxiang Pigs

This experiment aimed to study the effects of diets with different energy and protein levels on the growth performance,carcass traits and meat quality of Ningxiang pigs.A total of 72 Ningxiang piglets weighted 18 kg were selected and randomly divided into 3 groups with 4 replicates per group and 6 pigs per replicate.The control group was fed basal diets(protein:14.03%,12.06%and 11.01%in early,medium and later stages;digestible energy:12.15 MJ/kg in whole stage).The experimental group A fed low-nutrition test diets which protein levels decreased by 2%respectively in three stages and digestible energy level decreased by 1.25 MJ/kg in whole stage based on basal diets.Similarly,the experimental group B fed ultra-low nutrition test diets with protein levels decreased by 3%respectively and digestible energy level decreased by 2.50 MJ/kg based on basal diets.The duration of the experiment was 180 d.The results showed as follows:1)feed to gain ratio and average daily gain of the experimental group were significantly higher than those of the control group(P<0.05);throughout the whole period,there were no significantly difference in growth performance among the groups(P>0.05).2)The fat percentage of the experimental group B was significantly lower than that of the control group and the experimental group A(P<0.05),and the lean meat rate showed an upward trend.Compared with the control group,the vertical length of the carcass of the experimental groups was significantly increased(P<0.01);the oblique length and skin thickness of the carcass of the experimental group B were significantly increased(P<0.05).3)The pH 1 h after slaughter of the longissimus dorsi muscle of the experimental group decreased significantly(P<0.05),and other meat quality traits were not significantly different among the groups(P>0.05).It can be seen that reducing dietary nutrition level has no obviously negative impact on growth performance and meat quality,and can improve slaughter performance and carcass composition.Furthermore,the ultra-low nutrition diet is more effective than the low-nutrition diet.