日粮蛋白质水平对冬毛期雌性黑貂营养物质消化率及毛皮质量的影响

选择健康的90日龄雌性黑貂60只,平均体质量(0.862　1±0.086　6)kg,随机分为6组,每组10个重复,研究不同的蛋白质水平对冬毛期雌性黑貂(Mstula vision)蛋白质的消化代谢规律及毛皮质量的影响。各组水貂饲粮蛋白质水平分别为26％(Ⅰ组)、28％(Ⅱ组)、30％(Ⅲ组)、32％(Ⅳ组)、34％(Ⅴ组)和36％(Ⅵ组)。结果表明:Ⅱ组水貂的采食量和粪干物质排泄量显著高于与Ⅲ组 (P<0.05),Ⅲ组的干物质消化率极显著高于Ⅱ(P<0.01);净蛋白利用率指标上,Ⅲ组极显著高于Ⅱ组水貂 (P<0.01),Ⅰ组、Ⅳ组和Ⅴ组显著高于Ⅱ组(P<0.05);Ⅲ组的蛋白质生物学价值极显著高于Ⅱ组水貂(P<0.01),Ⅲ组显著高于Ⅵ组水貂 (P<0.05),其他各组间差异不显著(P>0.05);Ⅱ组、Ⅲ组和Ⅳ组水貂皮长显著高于Ⅰ组(P<0.05)。结果提示,饲粮中的蛋白质含量达到30％(Ⅲ组)时,水貂的蛋白质生物学价值和净蛋白利用率最好,基本满足冬毛期雌性黑貂对蛋白质的需求;饲料中的蛋白质低于28％(Ⅱ组)时,水貂的皮张面积明显减小。

Effect of Diets with Different Protein Levels on Digestibility of Nutrition Substance and Fur Quality in Female Mink at Fur Development Period

The experiment was conducted to study the effect of diets with different protein levels on digestibility of nutrition substance and fur quality in female mink at the period of fur quality. Sixty of 90-day female mink, weighting an average of （0.862　1±0.086　6) kg, were randomly assigned into six groups with ten replicates and one mink with each pen. The treatments were individually fed with26%(Ⅰ), 28%(Ⅱ), 30%(Ⅲ), 32%(Ⅳ), 34%(Ⅴ) and 36%(Ⅵ) protein levels in diets. The period of trial lasted for 100 days. The results showed that compared withgroup Ⅲ, group Ⅱhad significant differences in feed intake and dry matter of fence drain(P<0.05), greatly significant difference in digestibility of dry matter(P<0.01). On the item of net protein usage ratio, there was greatly significant difference between group Ⅱand group Ⅲ (P<0.01) and significant difference when  groupⅡ was compared with groupsⅠ, Ⅳ and Ⅴ(P<0.05). The biological value of protein has greatly significant difference between groupⅡand groupⅢ (P<0.01) and significant difference between groupⅢand groupⅣ(P<0.05), the others had no difference(P>0.05). The fur length had significant difference when groupⅠwascompared with groupsⅡ, Ⅲ and Ⅳ (P<0.05). The results indicated that  group Ⅲhad the best production performance in the biological value of protein and net protein usage when the protein level was 30% in the diet, basically satisfiedwith the requirements of female mink at the period of fur development. The fur length was obviously reduced when the protein level was lower than 28%.