低蛋白质饲粮中添加DL-蛋氨酸和赖氨酸对冬毛期蓝狐生产性能、氮平衡及毛皮质量的影响

本文旨在探讨低蛋白质饲粮中添加DL-蛋氨酸和赖氨酸对冬毛生长期蓝狐生长性能、氮平衡和毛皮质量的影响,并研究低蛋白质饲粮中蛋氨酸和赖氨酸的最适添加量.对照组饲粮蛋白质水平为27%(P27),低蛋白质饲粮蛋白质水平为19%(P19),选择健康的生长后期雄性蓝狐120只(17周龄左右),随机分成10组,每组12只.本试验采用3×3双因子交叉试验设计,有3个赖氨酸水平(0.3%、0.5%、0.7%)和3个含硫氨基酸水平(0.4%、0.6%、0.8%),试验组编号分别为P27、L1M1、L1M2、L1M3、L2M1、L2M2、L2M3、L3M1、L3M2和L3M3,饲养试验试验期为61 d(2007-10-12～2007-12-12).结果表明,如果考虑蓝狐平均日增重、日氮沉积、氮沉积率,0.6%的蛋氨酸水平最佳;如果考虑日氮沉积和毛皮质量,0.3%和0.5%的赖氨酸水平最佳;如果考虑氮的表观消化率、日粪氮排出量,0.3%的赖氨酸水平最佳;各处理蓝狐的毛皮质量与对照组差异不显著(P＞0.05).综合各项指标,L1M2 (0.3% Lys×0.6% Met)组蓝狐生产性能最佳;低蛋白质饲粮中添加蛋氨酸和赖氨酸不影响冬毛期蓝狐的生产性能;应用低蛋白质饲粮降低了排泄物中氮的含量,减轻了环境污染,节约了蛋白质资源.

Effects of Low-protein, DL-methionine and Lysine-supplemented Diets on Growth Performance, N-balance and Fur Characteristics of Blue Foxes (Alopex lagopus) during the Growing-furring Period

An experiment was carried out to examine the effects of low-protein diets supplemented with different levels of DL-methionine (Met) and Lysine (Lys) on growth performance and fur characteristics of growing-furring blue foxes in order to find the optimal dietary supplementation levels of Met and Lys. For two protein levels, conventional 27% (P27) and low 19% (P19), the measured protein contents of the diets were 271.2 and 189.4 g/kg on dry matter basis, respectively, and the low-protein diets were supplemented with Met (0.3%, 0.5%, 0.7%) and Lys (0.4%, 0.6%, 0.8%). An entirely random experimental design was adopted with two factors (3×3) and totally 10 groups (P27, L1M1, L1M2, L1M3, L2M1, L2M2, L2M3, L3M1, L3M2 and L3M3). From mid-September to pelting, based on the average daily gain, daily N retention, N retention ratio and the performance of blue foxes in different groups, 0.6% Met supplementation in low-protein diet was optimum; based on the daily N retention, N biological value and the quality of the fur, 0.3% and 0.5% Lys supplementation were optimum; based on the N apparent digestibility and daily N output, 0.3% Lys supplementation was optimum. No significant differences were observed in fur characteristics of blue foxes in all groups (P＞0.05). In this experiment, the performance of blue foxes in L1M2 (0.3% Lys×0.6% Met) group was better than that in the other groups, which indicates that low-protein diets supplemented with DL-methionine and lysine for blue foxes can be beneficial to reduce feed expenses and nitrogen emission to the environment.