饲粮代谢能和粗蛋白质水平对冬毛期雄性水貂生产性能、氮代谢及能量利用率的影响

Effects of Dietary Metabolic Energy and Crude Protein Levels on Performance,Nitrogen Metabolism and Energy Utilization of Male Minks during Winter Fur-Growing Period

本试验旨在研究饲粮代谢能(ME)和粗蛋白质(CP)水平对冬毛期雄性水貂生产性能、氮代谢及能量利用率的影响,以明确冬毛期水貂饲粮ME和CP的适宜水平,完善我国水貂营养标准。选取(145±5)日龄、体重[(1765±26)g]相近的健康雄性黑水貂180只,随机分为6组,每组30个重复,每个重复1只。采用2×3双因素试验设计,饲粮CP水平分别为30.45%、34.58%,饲粮ME水平分别为13.11、14.94、16.76 MJ/kg。预试期4 d,正试期68 d。结果表明:1)30.45%CP组水貂末重、平均日增重(ADG)、平均日采食量(ADFI)、料重比(F/G)、体长和鲜皮长极显著低于34.58%CP组(P<0.01)。13.11 MJ/kg ME组末重、ADG极显著低于14.94和16.76 MJ/kg ME组(P<0.01),14.94 MJ/kg ME组ADFI、F/G、体长和鲜皮长极显著或显著高于13.11和16.76 MJ/kg ME组(P<0.01或P<0.05)。饲粮CP和ME水平对水貂末重、ADG、ADFI、F/G、体长和鲜皮长具有显著或极显著交互作用(P<0.05或P<0.01)。2)34.58%CP组食入氮、粪氮、尿氮、氮沉积显著或极显著高于30.45%CP组(P<0.05或P<0.01)。14.94 MJ/kg ME组食入氮显著或极显著高于13.11和16.76 MJ/kg ME组(P<0.01或P<0.05)。饲粮CP和ME水平对水貂净蛋白质利用率和蛋白质生物学价值无显著交互作用(P>0.05),对食入氮、粪氮、尿氮、氮沉积具有极显著交互作用(P<0.01)。3)34.58%CP组消化能代谢率极显著低于30.45%CP组(P<0.01),34.58%CP组总能、粪能、尿能、消化能、ME均极显著高于30.45%组(P<0.01)。13.11 MJ/kg ME组总能、消化能、ME、总能消化率、总能代谢率和消化能代谢率显著或极显著低于14.94和16.76 MJ/kg ME组(P<0.05或P<0.01)。饲粮CP和ME水平对水貂总能、粪能、尿能、消化能、ME、总能消化率、总能代谢率和消化能代谢率具有显著或极显著交互作用(P<0.05或P<0.01)。综上所述,在本试验条件下,饲粮CP水平为34.86%、ME水平为15.08 MJ/kg时水貂能够获得较好的末重、ADG、F/G、体长和鲜皮长,从而提高了水貂的生产性能。

The purpose of this experiment was to study the effects of dietary metabolic energy(ME)and crude protein(CP)levels on performance,nitrogen metabolism and energy utilization of male minks during winter fur-growing period,so as to determine the optimum dietary ME and CP levels of male minks during winter fur-growing period,and improve China’s mink nutrition standards.One hundred and eighty healthy male minks at(145±5)days of age with similar body weight[(1765±26)g]were randomly assigned into 6 groups with 30 replicates per group and 1 mink per replicate.A 2×3 two-factor factorial design was adopted in this study,dietary CP levels were 30.45% and 34.58%,respectively,and dietary ME levels were 13.11,14.94 and 16.76 MJ/kg,respectively.The pre-trial period lasted for 4 days and the trial period lasted for 68 days.The results showed as followed:1)the final weight,average daily gain(ADG),average daily feed intake(ADFI),feed to gain ratio(F/G),body length and fresh fur length in 30.45% CP group were significantly lower than those in 34.58% CP group.The final weight and ADG in 13.11 MJ/kg ME group were significantly lower than those in 14.94 and 16.76 MJ/kg ME groups(P<0.01),and the ADFI,F/G,body length and fresh fur length in 14.94 MJ/kg ME group were significantly higher than those in 13.11 and 16.76 MJ/kg ME groups(P<0.05 or P<0.01).Dietary CP and ME levels had significant interactions on final weight,ADG,ADFI,F/G,body length and fresh fur length of minks(P<0.05 or P<0.01).2)The nitrogen intake,fecal nitrogen,urine nitrogen and nitrogen deposition in 34.58% CP group were significantly higher than those in 30.45% CP group(P<0.05 or P<0.01).The nitrogen intake in 14.94 MJ/kg ME group was significantly higher than that in 13.11 and 16.76 MJ/kg ME groups(P<0.05 or P<0.01).Dietary CP and ME levels had no significant interaction on net protein utilization and biological value of protein of mink(P>0.05),but had significant interaction on nitrogen intake,fecal nitrogen,urine nitrogen and nitrogen deposition(P<0.01).3)The digestibility energy metabolic rate in 34.58% CP group was significantly lower than that in 30.45% CP group(P<0.01),and the gross energy,fecal energy,urine energy,digestive energy and ME in 34.58% CP group were significantly higher than those in 30.45% CP group(P<0.01).The gross energy,digestible energy,ME,gross energy digestibility,gross energy metabolic rate and digestible energy metabolic rate in 13.11 MJ/kg ME group were significantly lower than those in 14.94 and 16.76 MJ/kg ME groups(P<0.05 or P<0.01).Dietary CP and ME levels had significant interactions on the gross energy,fecal energy,urine energy,digestible energy,ME,gross energy digestibility,gross energy metabolic rate and digestible energy metabolic rate of minks.Considering all the factors,under the conditions of this experiment,when dietary CP level is 34.86% and ME level is 15.08 MJ/kg,the minks can get better final weight,AGD,F/G,body length and fresh fur length,thus,the performance of mink is improved.