低蛋白日粮补充苏氨酸对肉鸭生长性能、肌肉发育及经济效益的影响

Effects of low protein diet supplemented with threonine on growth performance,muscle development and economic benefit of meat ducks

文中旨在探究低蛋白日粮补充苏氨酸对肉鸭生长性能、肌肉发育及经济效益的影响。试验将1000羽1日龄的健康肉鸭分为4组,每组10个重复,每重复25羽,对照组(Ⅰ组)饲喂正常蛋白质水平日粮,试验组Ⅱ、Ⅲ和Ⅳ在基础日粮基础上降低约2%的粗蛋白质水平的同时补充蛋氨酸(Met)和赖氨酸(Lys)以使各组间Met和Lys水平保持一致。并分别额外补充0%、0.10%和0.20%苏氨酸(Thr)的试验日粮。与对照组相比,降低2%的粗蛋白质水平组肉鸭FBW显著降低5.76%(P<0.05);与低蛋白日粮组相比,添加0.20的Thr组肉鸭末体重(FBW)显著提高2.70%(P<0.05),但仍低于对照组3.21%(P<0.05);低蛋白日粮组,添加0%~0.20%Thr组肉鸭平均日增重(ADG)分别显著降低5.89%、4.52%和3.29%(P<0.05)料重比(F/G)分别显著提高7.65%、5.09%和3.91%(P<0.05)。与对照组相比,低蛋白日粮组补充0%~0.20%的Thr组肉鸭的胸肌率显著降低(P<0.05);低蛋白日粮组补充0%~0.20%的Thr组肉鸭的腿肌率显著降低(P<0.05),与0%和0.10%的Thr组相比,0.20%的Thr组肉鸭腿肌率显著提高(P<0.05);低蛋白日粮组补充0%~0.20%的Thr组肉鸭的肌肉粗蛋白含量显著降低(P<0.05),与0%的Thr组相比,0.10和0.20%的Thr组肉鸭肌肉粗蛋白含量显著提高(P<0.05)本试验各组饲料价格分别为3.2701、3.1783、3.1855和3.1927元/kg;低蛋白日粮添加0%~0.0820%的Thr组饲料总成本较对照组显著降低,且组内差异不显著(P>0.05);综合计算后,本试验各组毛利润分别为15.33、13.51、14.15和14.51元,低蛋白日粮添加0%~0.0820%的Thr组毛利润较对照组显著降低(P<0.05)。总之,日粮蛋白质水平对肉鸭生长影响显著,补充0.10%的Thr能部分恢复低蛋白质水平导致的生长发育迟缓。

This study was conducted to investigate the effects of low protein diet supplemented with threonine on growth performance,muscle development and economic benefits of meat ducks.1000 one-day-old healthy ducks were divided into 4 groups with 1 group per 10 replicates and 25 ducks per replicate.The control group(groupⅠ)was fed with a normal protein level diet,and the experimental groupsⅡ,ⅢandⅣwere fed with a 2%reduction of crude protein level on the basis of the basic diet while supplemented with Met and Lys to maintain the consistency of Met and Lys levels among the groups.The experimental diets were supplemented with 0%,0.10%and 0.20%threonine,respectively.Compared with the control group,FBW of ducks in 2%crude protein level group was significantly decreased by 5.76%(P<0.05);Compared with low protein diet group,FBW of ducks in 0.20 Thr group was significantly increased by 2.70%(P<0.05),but was still lower than that in control group by 3.21%(P<0.05).In the low protein diet group,ADG was significantly decreased by 5.89%,4.52%and 3.29%(P<0.05)and F/G was significantly increased by 7.65%,5.09%and 3.91%(P<0.05),respectively,in the 0%to 0.20%Thr groups.Compared with the control group,the breast muscle percentage of ducks supplemented with 0%~0.20%Thr in low protein diet group was significantly decreased(P<0.05);The thigh muscle percentage of ducks in low protein diet group supplemented with 0%to 0.20%Thr group was significantly decreased(P<0.05),and compared with 0%and 0.10%Thr groups,the thigh muscle percentage of ducks in 0.20%Thr group was significantly increased(P<0.05).The muscle crude protein content of ducks supplemented with 0%to 0.20%Thr in low protein diet group was significantly decreased(P<0.05),compared with 0%Thr group,The muscle crude protein content of ducks in 0.10 and 0.20%Thr groups was significantly increased(P<0.05).The feed prices of all groups were 3.2701,3.1783,3.1855 and 3.1927 yuan/kg,respectively.The total feed cost of low protein diet supplemented with 0%to 0.0820%Thr group was significantly lower than that of control group,and there was no significant difference among groups(P>0.05).After comprehensive calculation,the gross profit of each group in this experiment was 15.33,13.51,14.15 and 14.51 yuan,respectively.The gross profit of low protein diet supplemented with 0%to 0.0820%Thr group was significantly lower than that of control group(P<0.05).In conclusion,dietary protein level has a significant effect on the growth of meat ducks,and adding 0.10%Thr can partially restore the growth retardation caused by low protein level.