饲粮粗蛋白质和粗脂肪水平对冬毛期雄性水貂生长性能、营养物质消化率及氮代谢的影响

本试验旨在研究饲粮粗蛋白质(CP)和粗脂肪(EE)水平对冬毛期雄性水貂生长性能、营养物质消化率及氮代谢的影响,以明确冬毛期水貂饲粮CP和EE的适宜水平。试验采用2×3因子试验设计,即2个CP水平(32%和36%)和3个EE水平(10%、20%和30%),共配制6种试验饲粮。选取84只(120±5)日龄健康雄性水貂,随机分成6组,每组14个重复,每个重复1只。预试期7 d,正试期85 d。结果表明:32%CP组水貂平均日增重(ADG)、蛋白质消化率、脂肪消化率、碳水化合物消化率及氮代谢各指标均显著或极显著低于36%CP组(P0.05或P0.01)。30%EE组水貂末重、ADG和氮沉积含量显著或极显著高于10%EE组(P0.05或P0.01);30%EE组水貂平均日采食量、料重比、干物质消化率、蛋白质消化率、碳水化合物消化率、食入氮含量和粪氮排出量显著或极显著低于10%EE组(P0.05或P0.01)。饲粮CP和EE水平对水貂脂肪消化率有显著交互作用(P0.05)。综合以上指标,在本试验条件下,饲粮CP水平为36%、EE水平为20%或30%时,冬毛期水貂可获得较佳的生长性能,且能够提高水貂对蛋白质的利用率。

Effects of Dietary Crude Protein and Ether Extract Levels on Growth Performance,Nutrient Digestibility and Nitrogen Metabolism of Male Minks during Winter Fur-Growing Period

This experiment was conducted to investigate the effects of dietary crude protein ( CP) and ether ex-tract ( EE) levels on growth performance, nutrient digestibility and nitrogen metabolism of male minks during winter fur-growing period, in order to determine the optimum dietary CP and EE levels of male minks during winter fur-growing period. A 2×3 factorial design was adopted in this test, six experimental diets were prepared with two CP levels ( 32% and 36%) and three EE levels ( 10%, 20% and 30%) . Eighty-four healthy male minks at (120±5) days of age were randomly assigned into 6 groups with 14 replicates per group and 1 mink per replicate. The adaptation period lasted for 7 days and the formal period lasted for 85 days. The results showed as follows:the average daily gain ( ADG) , protein digestibility, fat digestibility, carbohydrate digesti-bility and nitrogen metabolism indices of minks in 32% CP group were significantly lower than those in 36%CP group ( P<0.05 or P<0.01) . The final weight, ADG and nitrogen deposition content of minks in 30% EE group were significantly higher than those in 10% EE group ( P<0.05 or P<0.01) , the average daily feed in-take, ratio of feed to gain, dry matter digestibility, protein digestibility, carbohydrate digestibility, nitrogen in-take content and fecal nitrogen output of minks in 30% EE group were significantly lower than those in 10%EE group (P<0.05 or P<0.01). Dietary CP and EE levels had significant interaction on fat digestibility of minks ( P<0.05) . Considering all the factors, when dietary CP level is 36%, EE level is 20% or 30% under the condition of this experiment, the male minks during winter fur-growing period can get the better growth performance, and can improve protein utilization of minks.