本文旨在研究饲粮中添加螯合锌对冬毛期貉生长性能、营养物质表观消化率、血清指标、毛皮品质的影响。选择健康冬毛期貉120只,随机分为4组,即3个试验组(Ⅰ组、Ⅱ组、Ⅲ组)与1个对照组(Ⅳ组),每组30只(公母各占1/2)。以蛋氨酸锌为螯合锌源,一水合硫酸锌(ZnSO₄·H₂O)为无机锌源,Ⅰ组、Ⅱ组、Ⅲ组、Ⅳ组分别饲喂基础饲粮+50 mg/kg 蛋氨酸锌+20 mg/kg ZnSO₄·H₂O、基础饲粮+60 mg/kg蛋氨酸锌+10 mg/kg ZnSO₄·H₂O、基础饲粮+70 mg/kg蛋氨酸锌、基础饲粮+70 mg/kg ZnSO₄·H₂O(数据均为锌含量,基础饲粮中锌含量为42.89 mg/kg)。试验期为55 d。结果表明:1)3个试验组的终末体重和饲料转化率均显著或极显著均高于对照组(P<0.05或P<0.01)。Ⅱ组、Ⅲ组的平均日增重显著高于对照组(P<0.05)。2)3个试验组的粗蛋白质表观消化率与对照组相比无显著差异(P>0.05),但粗脂肪表观消化率显著高于对照组(P<0.05)。3)3个试验组的血清锌含量、碱性磷酸酶活性均极显著高于对照组(P<0.01)。4)与对照组相比,3个试验组的颈部、背部、臀部针毛长度以及绒毛长度与绒毛直径均增加,但针毛直径降低,其中Ⅲ组颈部、背部、臀部针毛直径显著或极显著小于对照组(P<0.05或P<0.01)。5)3个试验组的皮张单位面积重量显著或极显著高于对照组(P<0.05或P<0.01)。综上所述,饲粮中添加螯合锌后冬毛期貉体重、平均日增重、饲料转化率、粗脂肪表观消化率、皮张品质均有提升,但针毛直径减小;当螯合锌添加量为70 mg/kg时,针毛发生卷曲,建议生产中螯合锌添加量为60 mg/kg(饲粮总锌含量为102.89 mg/kg)。

The present study assessed the influences of chelating zinc on growth performance, nutrient apparent digestibility, serum indices and fur quality of raccoon dogs during winter-furring period.A total of 120 healthy winter-furring raccoon dogs were randomly selected and divided into 4 groups, and each group contained 30 animals with half male and half female.Three groups were assigned as the experimental groups (groups Ⅰ, Ⅱ and Ⅲ) and the fourth group was used as control group (group Ⅳ).Methionine chelated zinc (Met-Zn) and ZnSO₄·H₂O were used as chelating and inorganic zinc sources, respectively.The raccoon dogs in groups Ⅰ, Ⅱ, Ⅲ and Ⅳ were fed basal diet+50 mg/kg Met-Zn+20 mg/kg ZnSO₄·H₂O, basal diet+60 mg/kg Met-Zn+10 mg/kg ZnSO₄·H₂O, basal diet+70 mg/kg Met-Zn, basal diet+70 mg/kg ZnSO₄·H₂O (the data were zinc content, and the zinc content in the basal diet was 42.89 mg/kg), respectively.The experiment lasted for 55 days.The results showed as follows: 1) the final body weight and feed conversion rate in the three experimental groups were significantly higher than those in the control group (P<0.05 or P<0.01), and the average daily gain in groups Ⅱ and Ⅲ was significantly higher than that in the control group (P<0.05).2) No significant difference was observed in the apparent digestibility of crude protein between all experimental groups and the control group (P>0.05).However, the apparent digestibility of ether extract was significantly higher in experimental groups than that in the control group (P<0.05).3) Serum znic content and alkaline phosphatase activity in the control group were significantly lower than those in all experimental groups (P<0.01).4) Experimental groups tended to have longer guard hair, under fur and the diameter of under fur in neck, backside and buttocks compared with the control group.However, the diameter of guard hair was decreased in experimental groups compared with the control group, and the diameter of guard hair in neck, backside and buttocks in group Ⅲ was significantly shorter than that in the control group.(P<0.05).5) The weight of skin per unit area in three experimental groups was significantly higher than that in the control group (P<0.01 or P<0.01).These results suggest that adding chelating zinc to the diet can improve the body weight, average daily gain, feed conversion rate, ether extract apparent digestibility and fur quality of raccoon dogs although, the guard hair diameter tends to become thinner.The dosage of additive chelating zinc at 70 mg/kg may lead to slight curling of guard hair.Therefore, we recommend to add chelating zinc at the dosage of 60 mg/kg (total content of zinc in the diet is 102.89 mg/kg) in practice.