日粮蛋白质水平对云南半细毛羊空怀母羊能量代谢的影响

Effects of dietary protein level on energy metabolism of non-pregnant Yunnan semi-fine wool ewes

为研究日粮蛋白质水平对云南半细毛羊空怀母羊能量代谢的影响,试验选择25只云南半细毛羊空怀母羊,平均分为5个组,分别饲喂蛋白质水平为8.4%、10.0%、12.3%、13.6%、15.9%的日粮,用全收粪法进行消化代谢试验,试验期共19 d,预试期14 d,正试期5 d。结果表明:(1)日粮蛋白质水平对总能摄入量无显著影响(P>0.05)。(2)从组1到组5粪能逐渐下降,且组3、组4、组5较组1分别降低了10.5%、11.4%、13.7%(P<0.05),组5较组2降低了9.5%(P<0.05)。(3)从组1到组5尿能逐渐增加,除组2与组1、组3间差异不显著(P>0.05)外,其余组间差异极显著(P<0.01)。(4)组4和组5总能消化率较组1极显著提高13.2%和11.8%(P<0.01),其余各组差异不显著(P>0.05)。组4总能代谢率较组1极显著提高9.8%(P<0.01),其余各组差异不显著(P>0.05)。对于消化能代谢率,组1和组2差异不显著(P>0.05),组3、组4和组5依次显著降低(P<0.05)。(5)蛋白质采食量与总能消化率、消化能代谢率间的回归方程分别为:Y=0.917X+45.872(R^(2)=0.853);Y=-0.370X+87.735(R^(2)=0.899)。综上,日粮蛋白质水平与粪能呈负相关,与尿能呈正相关。日粮蛋白质水平为13.6%时,总能消化率和总能代谢率均较8.4%蛋白质水平组极显著提高。总能消化率随蛋白质采食量的提高而线性升高,消化能代谢率则随蛋白质采食量的提高而线性降低。

This experiment was conducted to study the effects of dietary protein levels on energy metabolism of non-pregnant Yunnan semi-fine wool ewes.Twenty-five non-pregnant Yunnan semi-fine wool ewes were divided into five groups with five replicates per group.The groups 1 to 5 were fed diets with five different levels of protein(8.4%,10.0%,12.3%,13.6%,15.9%,respectively).All the tested ewes were reared for 19 d,including a pre-test period of 14 d and a digestion metabolism experiment of 5 d by total collection of feces and urine.The results showed as follows:(1)Dietary protein level had no significant effects on the gross energy(GE)apparent digestibility(P>0.05).(2)The fecal energy(FE)were reduced with the dietary protein level increasing.And compared with group 1,the FE of groups 3,4 and 5 were reduced by 10.5%,11.4%and 13.7%(P<0.05).The FE of group 5 was reduced by 9.5%compared with group 2(P<0.05).(3)With the increase of dietary protein level,the urinary energy increased,and there was significant difference among other groups(P<0.01)except group 2 and groups 1,3(P>0.05).(4)The gross energy(GE)apparent digestibility of groups 4 and 5 were significantly 13.2%and 11.8%higher than that of group 1(P<0.01),but there was no significant difference among other groups(P>0.05).The GE metabolic rate of group 4 was significantly 9.8%higher than that of group 1(P<0.01),but there was no significant difference among other groups(P>0.05).The digestible energy(DE)metabolic rate reduced gradually from group 3 to group 5(P<0.05),and there was no significant difference between group 1 and group 2(P>0.05).(5)The regression formulas between GE apparent digestibility,DE metabolic rate and protein intake were as follow:Y=0.917X+45.872(R^(2)=0.853),Y=-0.370X+87.735(R^(2)=0.899).According to above findings,dietary protein level was negatively correlated with fecal energy but positively correlated with urine energy.When the dietary protein level was increased from 8.4%to 13.6%,the GE apparent digestibility and GE metabolism rate increased significantly.The GE apparent digestibility increased linearly with the increase of protein intake,but the DE metabolic rate decreased linearly with the increase of protein intake.