饲粮铜水平对冬毛期雌性蓝狐生长性能、营养物质消化率、血清生化指标及毛皮品质的影响

本试验旨在研究饲粮铜水平对冬毛期雌性蓝狐生长性能、营养物质消化率、血清生化指标及毛皮品质的影响。试验选取115日龄左右的健康雌性蓝狐50只,随机分成5组,每组10个重复,每个重复1只。以五水硫酸铜(Cu SO_4·5H_2O)为铜源,在基础饲粮中分别添加0、12.22、32.22、72.22、152.22 mg/kg的铜配成5种试验饲粮,5种试验饲粮铜水平分别为7.78(Ⅰ组,作为对照组)、20(Ⅱ组)、40(Ⅲ组)、80(Ⅳ组)、160 mg/kg(Ⅴ组)。预试期为7 d,正试期为60 d。结果表明:1)Ⅲ、Ⅳ和Ⅴ组蓝狐的平均日增重显著高于对照组(P0.05),料重比显著低于对照组(P0.05);各组蓝狐的终末体重及平均日采食量差异不显著(P0.05)。2)各组蓝狐的干物质消化率、蛋白质消化率及氮沉积差异不显著(P0.05);Ⅲ、Ⅳ组蓝狐的脂肪消化率显著高于对照组(P0.05),其他各组间差异不显著(P0.05);铜排出量随着饲粮铜水平的升高极显著的增加(P0.01)。3)Ⅴ组蓝狐血清总蛋白和白蛋白含量显著高于对照组和Ⅱ组(P0.05);Ⅴ组蓝狐血清尿素氮含量显著高于Ⅱ组(P0.05);各组蓝狐血清铜蓝蛋白活性差异不显著(P0.05),Ⅳ组蓝狐血清铜锌超氧化物歧化酶活性显著高于对照组及Ⅱ和Ⅲ组(P0.05)。4)Ⅴ组蓝狐肝脏铜含量显著高于对照组(P0.05),血清铜、锌、铁含量各组间差异不显著(P0.05)。5)饲粮铜水平并未显著影响蓝狐的体长和干皮长(P0.05);Ⅲ和Ⅴ组蓝狐针毛长和绒毛长显著大于Ⅱ和Ⅳ组(P0.05);Ⅴ组蓝狐皮张颜色显著深于对照组(P0.05)。由此可见,在饲粮中添加32.22 mg/kg铜即铜水平为40.00 mg/kg时,冬毛期雌性蓝狐可获得较好的生长性能、营养物质消化率及毛皮品质,同时铜的排放量较低。

Effects of Dietary Copper Level on Growth Performance,Nutrient Digestibility,Serum Biochemical Parameters and Fur Quality of Female Blue Foxes in Fur Development Period

An experiment was conducted to investigate the effects of dietary copper (Cu) level on growth performance,nutrient digestibility,serum biochemical parameters and fur quality of female blue foxes in fur development period.Sixty healthy ll5-day-old female blue foxes were randomly allocated to 5 groups with 10 replicates each group and 1 fox per replicate.The foxes in the five groups were fed experimental diets with Cu supplemental levels of O,12.22,32.22,72.22 and 152.22 mg/kg using copper sulfate pentahydrate (CuSO4 · 5H2O) as copper source,and the Cu levels in the experimental diets were 7.78 (group Ⅰ,as control group),20.00 (group Ⅱ),40.00 (group Ⅲ),80.00 (group Ⅳ) and 160.00 mg/kg (group Ⅴ),respectively.The pre-test period lasted for 7 days,and the trial lasted for 60 days.The results showed as follows:1) foxes in groups Ⅲ,Ⅳ and Ⅴ had higher average daily gain (ADG) and lower feed/gain (F/G) compared with those in control group (P＜0.05).Besides,dietary Cu level did not affect the average daily feed intake (ADFI) and final body weight (FBW) (P＞0.05).2) The digestibility of dry matter and protein,and nitrogen retention were not affected by dietary Cu level (P＞0.05).Foxes in groups Ⅲ and Ⅳ had higher fat digestibility compared with control group (P＜0.05).Cu output was significantly raised with the dietary Cu level increasing (P＜0.01).3) Serum total protein (TP) and albumin (ALB) contents in group Ⅴ were significantly higher than those in control group and group Ⅱ (P＜0.05).Serum urea nitrogen (UN) content in group Ⅴ was significantly higher than that in group Ⅱ (P＜0.05).The activity of serum Cu and zinc (Zn) superoxide dismutase (Cu-Zn SOD) in group Ⅳ was significantly higher than that in control group and group Ⅱ (P＜ 0.05),but no significant difference was found in serum ceruloplasmin (Cp) activity among the five groups (P＞0.05).4) Liver Cu content in group Ⅴ was significantly higher than that in control group (P＜0.05),but no significant differences were observed in serum Cu,Zn and iron (Fe) contents among the five groups (P＞ 0.05).5) The body length and dry fur length were not affected by dietary Cu level (P＞0.05).Guard hair length and underfur length in groups Ⅲ and Ⅴ were significantly higher than those in groups Ⅱ and Ⅳ (P＜ 0.05).Foxes in group Ⅴ had a darker fur color compared with control group (P＜0.05).It is concluded that diet supplemented with 32.22 mg/kg Cu (Cu level is 40.00 mg/kg) can promote growth performance,nutrient digestibility and fur quality of female blue foxes in fur development period.Meanwhile,Cu excretion is relatively low when foxes are fed 40.00 mg/kg Cu diet.