不同料水比的湿拌料对育成期银狐采食量、营养物质消化率、氮代谢及体重的影响

本试验旨在探讨不同料水比的湿拌料对育成期银狐采食量、营养物质消化率、氮代谢及体重的影响。试验选用平均体重为(3.44±0.19)kg的12周龄左右的健康银狐30只,随机分为3个组,每组10只,公母各占1/2。3组银狐分别饲喂料水比为1.0∶2.5(Ⅰ组)、1.0∶3.5(Ⅱ组)和1.0∶4.5(Ⅲ组)的湿拌料,试验期48 d。结果表明:1)随着湿拌料添加水分比例的升高,各周龄银狐的干物质平均日采食量均有不同程度的增加,其中Ⅲ组银狐干物质平均日采食量在14、15、17、18、19周龄时极显著高于Ⅰ组和Ⅱ组(P0.01),在16周龄时显著高于Ⅰ组(P0.05);Ⅲ组干物质总采食量极显著高于Ⅰ组和Ⅱ组(P0.01),且Ⅱ组也有高于Ⅰ组的趋势,但差异不显著(P0.05)。2)Ⅰ组干物质消化率显著高于Ⅲ组(P0.05);蛋白质消化率各组间差异不显著(P0.05),但Ⅰ组较Ⅱ组升高4.62%,Ⅱ组较Ⅲ组升高5.42%;脂肪消化率各组间差异不显著(P0.05),但Ⅰ组较Ⅲ组升高4.03%,Ⅱ组较Ⅲ组升高4.46%。3)食入氮表现为Ⅲ组极显著高于Ⅰ组和Ⅱ组(P0.01),Ⅱ组也有高于Ⅰ组的趋势,但差异不显著(P0.05);尿液量随着湿拌料添加水分比例的升高显著或极显著升高(P0.05或P0.01);氮沉积各组间差异不显著(P0.05);粪氮排出量表现为Ⅲ组显著高于Ⅰ组和Ⅱ组(P0.05),Ⅱ组高于Ⅰ组,但差异不显著(P0.05);随着湿拌料添加水分比例的升高,尿氮排出量有升高的趋势,而净蛋白质利用率有降低的趋势,但各组间差异不显著(P0.05);Ⅰ组蛋白质生物学价值显著高于Ⅱ组和Ⅲ组(P0.05)。4)不同料水比的湿拌料对银狐不同周龄平均体重、各阶段平均日增重、总增重均无显著影响(P0.05);对于料重比,Ⅱ组较Ⅲ组降低4.30%,Ⅰ组较Ⅱ组降低1.21%,但各组间差异不显著(P0.05)。综合各项指标,从降低环境污染和饲料成本以及保证银狐体增重的角度出发,育成期银狐湿拌料中料水比以1.0∶2.5为宜。

Effects of Different Ratios of Feed to Water of Wet Mash on Feed Intake,Nutrient Digestibility,Nitrogen Metabolism and Body Weight of Growing Silver Foxes

This experiment was conducted to study the effects of different ratios of feed to water of wet mash on feed intake, nutrient digestibility, nitrogen metabolism and body weight of growing silver foxes.Thirty 12-week-old healthy silver foxes with the average body weight of (3.44±0.19) kg were randomly assigned into 3 groups, and each group had 10 foxes ( half male and half female) .The silver foxes in the three groups were fed experimental diets with wet mash of ratios of feed to water of 1.0∶2.5 ( group Ⅰ) , 1.0∶3.5 ( group Ⅱ) and 1.0∶4.5 (group Ⅲ), respectively.The experiment lasted for 48 days.The results showed as follows:1) with the water ratio in wet mash increasing, the dry matter average daily feed intakes at different weeks old were increased by different degrees.Among them, the dry matter average daily feed intakes at 14, 15, 17, 18 and 19 weeks old in group Ⅲ were extremely significantly higher than those in groups Ⅰ and Ⅱ (P<0.01), and the dry matter average daily feed intake at 16 weeks old in group Ⅲ was significantly higher than that in group Ⅰ( P<0.05) .The dry matter total feed intake in groupⅢwas extremely significantly higher than that in groupsⅠ and Ⅱ( P<0.01) , and the dry matter total feed intake in groupⅡwas higher than that in groupⅠ, but the difference was not significant ( P>0.05) .2) The dry matter digestibility in group Ⅰ was significantly higher than that in group Ⅲ( P<0.05 ) .The protein digestibility in group Ⅰ was 4.62%higher than that in group Ⅱ, and that in group Ⅱ was 5.42%higher than that in group Ⅲ, but the differences were not signifi-cant ( P>0.05) .Compared with the group Ⅲ, the fat digestibility in group Ⅰ was 4.03%higher and that in groupⅡwas 4.46%higher, but the differences were not significant ( P>0.05) .3) Nitrogen intake in groupⅢwas extremely significantly higher than that in groups Ⅰand Ⅱ ( P<0.01) , and that in group Ⅱ was higher than that in group Ⅰ, but the difference was not significant (P>0.05).With the water ratio in wet mash in-creasing, the amount of urine was extremely significantly or significantly increased ( P<0.05 or P<0.01) .The fecal nitrogen output in groupⅢwas significantly higher than that in groupsⅠandⅡ( P<0.05) , and that in groupⅡwas higher than that in groupⅠ, but the difference was not significant ( P>0.05) .The urine nitrogen output, nitrogen retention and net protein utilization were not significantly different among all groups ( P>0.05) , but the urine nitrogen output had an increasing trend and the net protein utilization had a decreasing trend with the water ratio in wet mash increasing.The biological value of protein in groupⅠwas significantly higher than that in groupsⅡandⅢ( P<0.05) .4) The average body weight of different weeks old, the aver-age daily gain of each stage and the total weight gain were not significantly different among all groups ( P>0.05).The feed to gain in groupsⅡwas 4.30%lower than that in groupⅢ, and that in groupⅠwas 1.21%lower than that in groupⅡ, but there were no significant differences among all groups( P>0.05) .Considering all indices, the appropriate ratios of feed to water of wet mash is 1.0∶2.5, for growing silver foxes in terms of reducing feed expenses and environmental pollution, and maintaining body weight.