饲粮维生素B_2添加水平对冬毛期水貂生长性能、毛皮品质、营养物质消化率及氮代谢的影响

Effects of Dietary Vitamin B_2 Supplemental Level on Growth Performance,Fur Quality,Nutrient Digestibility and Nitrogen Metabolism of Minks during Winter Fur-Growing Period

本试验旨在研究饲粮维生素B2添加水平对冬毛期水貂生长性能、毛皮品质、营养物质消化率及氮代谢的影响。选取(135±5)日龄、体重相近的健康雄性短毛黑水貂90只,随机分为6组,每组15个重复,每个重复1只水貂。各组水貂分别饲喂在基础饲粮中添加0(Ⅰ组,对照组)、2.5(Ⅱ组)、5.0(Ⅲ组)、10.0(Ⅳ组)、20.0(Ⅴ组)、40.0 mg/kg(Ⅵ组)维生素B2的试验饲粮。预试期5 d,正试期63 d。结果表明:1)饲粮维生素B2添加水平对冬毛期水貂末重、平均日增重、平均日采食量无显著影响(P>0.05)。Ⅴ和Ⅵ组水貂料重比极显著低于对照组(P<0.01),与Ⅱ、Ⅲ和Ⅳ组差异不显著(P>0.05)。2)饲粮维生素B2添加水平对水貂毛皮品质评分和体长无显著影响(P>0.05)。Ⅴ组水貂绒毛长极显著高于其他各组(P<0.01),Ⅳ和Ⅴ组水貂针毛长极显著高于Ⅰ、Ⅱ、Ⅲ和Ⅵ组(P<0.01)。3)饲粮维生素B2添加水平对水貂干物质消化率、蛋白质消化率和脂肪消化率无显著影响(P>0.05)。4)饲粮维生素B2添加水平对水貂食入氮、尿氮、粪氮和沉积氮无显著影响(P>0.05)。Ⅴ组水貂净蛋白质利用率显著高于对照组(P<0.05),Ⅴ和Ⅵ组水貂蛋白质生物学价值显著高于Ⅰ、Ⅱ和Ⅲ组(P<0.05)。综合以上指标,从提高生长性能和减少饲料成本角度考虑,冬毛期水貂饲粮中维生素B2适宜添加水平为2.5 mg/kg(饲粮中维生素B2实际含量为5.49 mg/kg)。

This experiment was conducted to evaluate the effects of dietary vitamin B2 supplemental level on growth performance,fur quality,nutrient digestibility and nitrogen metabolism of minks during winter furgrowing period.Ninety healthy short black male minks at(135±5) days of age with an similar body weight were randomly divided into 6 groups with 15 replicates per group and 1 mink per replicate.Minks in the 6groups were fed the basal diets supplemented with 0(group Ⅰ,control group),2.5(group Ⅱ) 、5.0(groupⅢ),10.0(group Ⅳ),20.0(group Ⅴ) and 40.0 mg/kg(group Ⅵ) vitamin B2,respectively.The adaptation period lasted for 5 days and the formal period lasted for 63 days.The results showed as follows:1) dietary vitamin B2 supplemental level had no significant effects on the final weight,average daily gain and average daily feed intake of minks(P>0.05).The feed to gain ratio of minks of groups Ⅴ and Ⅵ was significantly lower than that of the control group(P<0.01),and had no significant difference compared with groups Ⅱ,Ⅲ andⅣ(P>0.05).2) Dietary vitamin B2 supplemental level had no significant effects on the fur quality score and body length of minks(P>0.05).The underwear length of minks of group Ⅴ was significantly higher than that of other groups(P<0.01),and the guard length of minks of groups Ⅳ and Ⅴ was significantly lower than that of groups Ⅰ,Ⅱ,Ⅲ and Ⅵ(P<0.01).3) Dietary vitamin B2 supplemental level had no significant effects on the dry matter digestibility,protein digestibility and fat digestibility of minks(P>0.05).4) Dietary vitamin B2 supplemental level had no significant effects on the nitrogen intake,urine nitrogen,fecal nitrogen and nitrogen deposition of minks(P>0.05).The net protein utilization of minks of group Ⅴ was significantly higher than that of the control group(P<0.05),and the biological value of protein of minks of groups Ⅴ and Ⅵ was significantly higher than that of groups Ⅰ,Ⅱ and Ⅲ(P<0.05).Considering all indices,considered the perspective of improving growth performance and reducing feed costs,the optimal dietary vitamin B2 supplemental level is 2.5 mg/kg(dietary vitamin B2 actual content is 5.49 mg/kg).