饲粮锰水平对冬毛期水貂生长性能、营养物质消化率及氮代谢的影响

Effects of Dietary Manganese Level on Growth Performance,Nutrient Digestibility and Nitrogen Metabolism of Mink during Winter Fur-Growing Season

本试验旨在探讨饲粮锰水平对冬毛期水貂生长性能、营养物质消化率及氮代谢的影响。选取日龄相近的健康雄性水貂75只,随机分为5组,每组15个重复,每个重复1只水貂,各组分别饲喂在基础饲粮中添加0(Ⅰ组)、50(Ⅱ组)、100(Ⅲ组)、300(Ⅳ组)和600 mg/kg(Ⅴ组)锰的试验饲粮,对应试验饲粮中锰水平为68.58、124.46、179.94、365.48、657.22 mg/kg。预试期7 d,正试期75 d。结果表明:Ⅳ组水貂的终末体重、平均日增重和体长均为最高,显著高于Ⅰ、Ⅱ和Ⅴ组(P<0.05),但与Ⅲ组差异不显著(P>0.05)。饲粮锰水平对水貂平均日采食量有显著影响(P<0.05),其中以Ⅲ组最高,显著高于Ⅰ组(P<0.05),与其他组差异不显著(P>0.05)。饲粮锰水平对水貂干物质和粗蛋白质消化率的影响不显著(P>0.05),对粗脂肪和碳水化合物消化率的影响显著或极显著(P<0.05或P<0.01),其中Ⅳ组粗脂肪消化率最高,Ⅲ组碳水化合物消化率最低。饲粮锰水平对水貂日食入氮量、日尿氮排出量、日氮沉积量的影响显著(P<0.05),其中Ⅳ组有最低日尿氮排出量和最高日氮沉积量。本试验条件下,当饲粮中添加300mg/kg锰,饲粮中锰水平为365.48 mg/kg时,能够提高冬毛期水貂生长性能,并且能够增加氮沉积,减少氮排放。

The effects of dietary manganese（ Mn） level on growth performance,nutrient digestibility and nitrogen（ N） metabolism of mink during winter fur-growing season was studied in this experiment. Seventy-five healthy male mink with the samilar age were randomly divided into 5 groups with 15 replicates per group and 1mink per replicate. The Mn levels of 0（ group Ⅰ）,50（ group Ⅱ）,100（ group Ⅲ）,300（ group Ⅳ） and600 mg / kg（ group Ⅴ） were added in the basal diet to prepare six experimental diets,respectively,and the corresponding Mn levels of those experimental diets were 68. 58,124. 46,179. 94,365. 48 and 657. 22 mg /kg. The trial lasted for 75 days with pretrial of 7 days. The results showed that final body weight,average daily gain（ ADG） and body length in the group Ⅳ were the highest,which significantly higher than those in groups Ⅰ,Ⅱ and Ⅴ（ P〈0. 05）,but there were no significant differences between groups Ⅳ and Ⅲ（ P〉0.05）. Dietary Mn level significantly affected the average daily feed intake（ ADFI）（ P〈0. 05）,and the groupⅢ was the highest one,but no significant difference with other groups except group Ⅰ（ P〉0. 05）. Dietary Mn level had no significantly effects on the digestibility of dry matter（ DM） and crude protein（ CP）（ P〉0.05）,but had significantly effects on the digestibility of ether extract（ EE） and carbohydrate（ P〈0. 05 or P〈0. 01）,and the highest EE digestibility was found in group Ⅳ and the lowest carbohydrate digestibility was found in group Ⅲ. Daily N intake,daily urinary N output and daily N retention were significantly affected by dietary Mn level（ P〈0. 05）,the highest daily N retention and the lowest daily urinary N output were all found in group Ⅳ. Under the conditions of this experiment,when the diet supplemented with 300 mg / kg Mn and Mn level in the diet is 365. 48 mg / kg,the growth performance and N retention of mink during winter fur-growing season can be improved,furthermore,the N emission also can be reduced.