饲粮维生素B2添加水平对育成期水貂生长性能、营养物质消化率及氮代谢的影响

Effects of Dietary Vitamin B_2 Level on Growth Performance,Nutrient Digestibilities and Nitrogen Metabolism of Growing Minks

本试验旨在研究饲粮维生素B_2添加水平对育成期水貂生长性能、营养物质消化率及氮代谢的影响。选取(65±5)日龄、体重[(1 213.38±72.72) g]相近的健康雄性短毛黑水貂96只,随机分为6个组,每组16个重复,每个重复1只水貂。采用单因素试验设计,各组饲粮维生素B_2添加水平分别为0(Ⅰ组)、2.5(Ⅱ组)、5.0(Ⅲ组)、10.0(Ⅳ组)、20.0(Ⅴ组)、40.0 mg/kg(Ⅵ组)。预试期7 d,正试期58 d。结果表明:1)饲粮维生素B_2添加水平显著影响水貂末重和料重比(P<0.05),极显著影响水貂平均日增重(P<0.01),其中以Ⅴ组平均日增重、末重最大,料重比最小。Ⅴ组平均日增重显著或极显著高于Ⅰ、Ⅱ、Ⅲ和Ⅳ组(P<0.05或P<0.01),Ⅴ、Ⅵ组料重比显著或极显著低于Ⅰ组(P<0.05或P<0.01),Ⅴ、Ⅵ组末重显著高于Ⅰ组(P<0.05)。2)饲粮维生素B_2添加水平极显著影响水貂粗蛋白质消化率和粗脂肪消化率(P<0.01),对水貂干物质采食量、干物质排出量和干物质消化率影响不显著(P>0.05)。Ⅵ组粗脂肪消化率最高,Ⅰ组最低,Ⅰ组极显著低于Ⅱ、Ⅴ和Ⅵ组(P<0.01)。Ⅴ组粗蛋白质消化率最高,极显著高于Ⅰ组(P<0.01)。3)饲粮维生素B_2添加水平显著影响育成期水貂氮沉积、净蛋白质利用率和蛋白质生物学价值(P<0.05),对食入氮、粪氮和尿氮影响不显著(P>0.05)。Ⅴ组净蛋白质利用率最高,显著高于Ⅰ和Ⅱ组(P<0.05),与Ⅲ、Ⅳ和Ⅵ组差异不显著(P>0.05)。Ⅴ组蛋白质生物学价值最高,Ⅴ和Ⅵ显著高于Ⅰ组(P<0.05),与Ⅱ、Ⅲ和Ⅳ组差异不显著(P>0.05)。Ⅵ组氮沉积最高,Ⅰ组最低,Ⅰ组显著低于Ⅴ和Ⅵ组(P<0.05),与Ⅱ、Ⅲ和Ⅳ组差异不显著(P>0.05)。综合各项指标,在本试验条件下,饲粮中维生素B_2添加水平为20.0 mg/kg(饲粮中维生素B_2水平为23.35 mg/kg)时,育成期水貂可以获得较好的生长性能及较高的营养物质消化率、氮利用率。

This experiment was conducted to evaluate the effects of dietary vitamin B 2 level on growth performance,nutrient digestibilities and nitrogen metabolism of growing minks.Ninety-six healthy short black male minks at the age of(65±5)days with the similar weight[(1 213.38±72.72)g]were randomly divided into 6 groups with 16 replicates per group and 1 mink per replicate.The experiment used a single factorial experiment design,and the dietary vitamin B 2 supplemental levels of 6 groups were 0(groupⅠ),2.5(groupⅡ),5.0(groupⅢ),10.0(groupⅣ),20.0(groupⅤ)and 40.0 mg/kg(groupⅥ),respectively.The adaptation period lasted for 7 days and the formal period lasted for 58 days.The results showed as follows:1)dietary vitamin B 2 level had significant effects on the final weight and feed to gain ratio of minks(P<0.05),and had extremely significant effect on the average daily gain of minks(P<0.01),the average daily gain and final weight of groupⅤwere the highest,while the feed to gain ratio was the lowest.The average daily gain of groupⅤwas significantly higher than that of groupsⅠ,Ⅱ,ⅢandⅣ(P<0.05 or P<0.01),the feed to gain ratio of groupsⅤandⅥwas significantly lower than that of groupⅠ(P<0.05 or P<0.01),the final weight of groupsⅤandⅥwas significantly higher than that of groupⅠ(P<0.05).2)Dietary vitamin B 2 level had extremely significant effects on the crude protein digestibility and ether extract digestibility of minks(P<0.01),while had no significant effects on the dry matter intake,dry matter output and dry matter digestibility of minks(P>0.05).The ether extract digestibility of groupⅥwas the highest,which of groupⅠwas the lowest,the ether extract digestibility of groupⅠwas extremely significantly lower than that of groupsⅡ,ⅤandⅥ(P<0.01).The crude protein digestibility of groupⅤwas the highest,which was extremely significantly higher than that of groupⅠ(P<0.01).3)Dietary vitamin B 2 level had significant effects on the nitrogen deposition,net protein utilization and the biological value of protein of minks(P<0.05),while had no significant effects on the nitrogen intake,fecal nitrogen and urine nitrogen of minks(P>0.05).The net protein utilization rate of groupⅤwas the highest,which was significantly higher than that of groupsⅠandⅡ(P<0.05),but had no significant difference with that of groupsⅢ,ⅣandⅥ(P>0.05).The biological value of protein of groupⅤwas the highest,which of groupsⅤandⅥwas significantly higher than that of groupⅠ(P<0.05),but had no significant difference with that of groupsⅡ,ⅢandⅣ(P>0.05).The nitrogen deposition of groupⅥwas the highest,which of groupⅠwas the lowest,the nitrogen deposition of groupⅠwas significantly lower than that of groupsⅤandⅥ(P<0.05),but had no significant difference with that of groupsⅡ,ⅢandⅣ(P>0.05).Considering all the factors,when dietary vitamin B 2 level is 20 mg/kg(dietary vitamin B 2 level is 23.35 mg/kg),growing minks can obtain the better growth performance and higher nutrient digestibilities and nitrogen utilization under the condition of this experiment.