不同蛋白质和脂肪水平颗粒料对冬毛期水貂生长性能、营养物质消化率、氮代谢和毛皮品质的影响

本试验旨在研究不同蛋白质和脂肪水平颗粒料对冬毛期水貂生长性能、营养物质消化率、氮代谢和毛皮品质的影响。选择(135±5)日龄的健康雄性水貂72只,随机分成6组,每组12只。采用双因子试验设计,分别按34%粗蛋白质、18%粗脂肪(Ⅰ组),34%粗蛋白质、16%粗脂肪(Ⅱ组),32%粗蛋白质、18%粗脂肪(Ⅲ组),32%粗蛋白质、16%粗脂肪(Ⅳ组),30%粗蛋白质、18%粗脂肪(Ⅴ组),30%粗蛋白质、16%粗脂肪(Ⅵ组)配制6种试验饲粮,并制成颗粒料。预试期7 d,正试期60 d。结果表明:Ⅰ组和Ⅲ组水貂的平均日增重(ADG)极显著高于Ⅱ组、Ⅳ组和Ⅵ组(P0.01);18%脂肪组水貂的末重显著高于16%脂肪组(P0.05),18%脂肪组水貂的ADG极显著高于16%脂肪组(P0.01)。Ⅵ组水貂的蛋白质消化率极显著低于其他各组(P0.01);18%脂肪组水貂的蛋白质消化率极显著高于16%脂肪组(P0.01);34%和32%蛋白质组水貂的蛋白质消化率极显著高于30%蛋白质组(P0.01)。Ⅱ组水貂的氮沉积和蛋白质生物学价值显著高于Ⅳ组(P0.05);Ⅱ组、Ⅲ组和Ⅳ组水貂的净蛋白质利用率显著高于Ⅵ组(P0.05);饲粮脂肪水平对水貂的氮代谢相关指标未产生显著影响(P0.05),饲粮蛋白质水平显著影响了水貂的净蛋白质利用率(P0.05)。34%和32%蛋白质组水貂的活体长显著高于30%蛋白质组(P0.05);34%蛋白质水貂的皮长显著高于30%蛋白质组(P0.05),但饲粮脂肪、蛋白质水平及两者的交互作用对水貂的皮长没有产生显著影响(P0.05)。综合试验结果得出:饲粮脂肪水平影响冬毛期水貂的末重,而饲粮蛋白质水平对冬毛期水貂的活体长具有影响;本试验条件下,冬毛期水貂饲喂脂肪水平为18%和蛋白质水平为32%~34%的颗粒料可获得较好的生长性能和毛皮品质。

Effects of Granulated Feeds with Different Protein and Fat Levels on Growth Performance,Nutrient Digestibility,Nitrogen Metabolism and Fur Quality of Minks in Pelting Period

This study was designed to investigate the effects of granulated feeds with different protein and fat levels on growth performance, nutrient digestibility, nitrogen metabolism and fur quality of minks in pelting period. Seventy?two (135±5)?day?old healthy male minks were divided into 6 groups and each group had 12 minks. Six experimental diets were prepared by double factorial experimental design with 34% crude protein ( CP) and 18% ether extract ( EE) ( group Ⅰ) , 34% CP and 16% EE ( group Ⅱ) , 32% CP and 18% EE ( group Ⅲ) , 32% CP and 16% EE ( group Ⅳ) , 30% CP and 18% EE ( group Ⅴ) , 30% CP and 16% EE ( group Ⅵ) , respectively, and all of them were made into granulated feeds. The pre?test period lasted for 7 days, and the trial lasted for 60 days. The results showed as follows: the average body weight ( ADG ) in groups Ⅰ and Ⅲ was significantly higher than that in groups Ⅱ, Ⅳ and Ⅵ (P<0.01). Minks in 18% fat group had significantly higher final body weight than 16% fat group (P<0.05), and the ADG in 18% fat group was significantly higher than that in 16% fat group ( P<0.01) . The minks in group Ⅵ had significantly lower protein digestibility than the others group (P<0.01), and 18% fat group had the same trend compared with 16% fat group ( P<0.01) . The protein digestibility in 34% and 32% protein groups was significantly high?er than that in 30% protein group ( P<0.01) . Nitrogen retention and protein biological value in group Ⅱ were significantly higher than those in group Ⅳ ( P<0.05) , the net protein utilization in groups Ⅱ, Ⅲ and Ⅵ was significantly higher than that in groupⅥ( P<0.05) . Dietary fat level had no significant effects on nitrogen me?tabolism related indices of minks ( P>0.05) , while dietary protein level had significantly effect on the net pro?tein utilization of minks ( P<0.05) . The live body length of minks in 34% and 32% protein groups was signifi?cantly higher than that in 30% protein group ( P<0.05) . The fur length of minks in 34% protein group was sig?nificantly longer than that in 30% protein group ( P<0.05) , but the dietary fat and protein levels and the inter?action of protein and fat levels had no significant effect on the fur long ( P>0.05) . Considering all the results, dietary fat level affects the final body weight of minks in pelting period, and the protein level affects the live body length. In the condition of this experiment, minks in pelting period have the optimized growth perform?ance and fur quality when fed granulated feeds with 18% fat and 32% to 34% protein.