饲粮中维生素E添加水平对育成期蓝狐生长性能、营养物质消化率、氮代谢和血清生化指标的影响

Effects of Vitamin E Supplemental Level on Growth Performance,Nutrient Digestibility,Nitrogen Metabolism and Serum Biochemical Indices of Blue Foxes during Growing Period

本试验旨在研究饲粮中添加不同水平维生素E对育成期蓝狐生长性能、营养物质消化率、氮代谢和血清生化指标的影响。选取65日龄体重相近的健康雄性蓝狐75只,随机分为5组,每组15个重复,每个重复1只。6组蓝狐分别饲喂在基础饲粮(本底维生素E含量为19.34 mg/kg)基础上添加0(对照组)、50、100、150和200 mg/kg维生素E(添加形式为50%α-生育酚醋酸酯)的饲粮。预试期10 d,正试期60 d。在试验第30天从每组选出8只蓝狐,进行连续4 d的消化代谢试验。结果显示:饲粮中维生素E添加水平对第56天体重以及第29~56天平均日增重(ADG)、平均日采食量(ADFI)和料重比(F/G)有显著影响(P<0.05)。随饲粮中维生素E添加水平的升高,第29~56天ADG持续升高,而F/G持续降低,且上述2个指标在添加100、200、300 mg/kg维生素E组与对照组之间均存在显著差异(P<0.05)。饲粮中维生素E添加水平对育成期蓝狐脂肪消化率有显著影响(P<0.05)。添加200 mg/kg维生素E组蓝狐的脂肪消化率显著高于其他各组(P<0.05)。饲粮中维生素E添加水平对育成期蓝狐血清超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活性有显著的影响(P<0.05)。添加100和150 mg/kg维生素E组蓝狐血清SOD活性显著高于添加50 mg/kg维生素E组(P<0.05);添加100、150、200 mg/kg维生素E组蓝狐血清GSH-Px活性显著高于对照组和添加50 mg/kg维生素E组(P<0.05)。饲粮中维生素E添加水平对育成期蓝狐血清免疫球蛋白G(IgG)含量有显著影响(P<0.05)。添加100、150、200 mg/kg维生素E组血清IgG含量显著高于对照组(P<0.05)。饲粮中维生素E添加水平对育成期对蓝狐血清总蛋白(TP)、白蛋白(ALB)、球蛋白(GLB)和甘油三酯(TG)含量有显著影响(P<0.05)。添加100、150和200 mg/kg维生素E组血清TG含量显著低于对照组(P<0.05),血清GLB含量显著高于对照组(P<0.05)。由此得出,饲粮中添加维生素E可提高育成期蓝狐的生长性能,促进脂肪消化,提高机体抗氧化能力,同时降低血清TG含量。在本试验条件下,综合考虑养殖成本和蓝狐生长性能,推荐育成期蓝狐饲粮中维生素E的添加水平为100~150 mg/kg。

This experiment was conducted to investigate the effects of vitamin E supplemental level on growth performance, nutrient digestibility, nitrogen metabolism and serum biochemical indices of blue foxes (Alopex lagopus) during growing period. Seventy-five male blue foxes at 65 days of age with the similar body weight were randomly assigned to 5 groups with 15 replicates per group and 1 fox per replicate. The foxes in 5 groups were fed diets with 5 supplemental levels[0 (control), 50, 100, 150 and 200 mg/kg] of vitamin E from α-tocopherol acetate (effective substance concentration of 50%) based on a basal diet (background vitamin E content was 19.34 mg/kg). The trial lasted for 60 days after 10 days adaption. Eight foxes were selected from each group, a digestion metabolism experiment was conducted for 4 days starting at the 30th day of the trial. The results showed as follows:1) dietary vitamin E supplemental level significantly affected the body weight of day 56, and the average daily gain (ADG), average daily feed intake (ADFI) and feed/gain (F/G) of day 29 to 56 (P<0.05). With the dietary vitamin E supplemental level increasing, the ADG of day 29 to 56 was improved continually, however, the F/G of day 29 to 56 was decreased continually. As well as, the two indicators of the groups supplemented with 100, 200 and 300 mg/kg vitamin E had significant difference with the control group (P<0.05). Dietary vitamin E supplemental level significantly affected the fat digestibility (P<0.05), and the fat digestibility of the group supplemented with 200 mg/kg vitamin E was significantly higher than that of other groups (P<0.05). The activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in serum were significantly affected by dietary vitamin E supplemental level (P<0.05). The activity of SOD in serum of groups supplemented with 100 and 150 mg/kg vitamin E was significantly higher than that of group supplemented with 50 mg/kg vitamin E (P<0.05). The activity of GSH-Px in serum of groups supplemented with 100, 150 and 200 mg/kg vitamin E were significantly higher than that of group supplemented with 50 mg/kg vitamin E and control group (P<0.05). The content of immunoglobulin G (IgG) in serum was affected by dietary vitamin E supplemental level (P<0.05). The contents of IgG in serum of groups supplemented with 100, 150 and 200 mg/kg vitamin E were significantly higher than that of control group (P<0.05). Dietary vitamin E supplemental level significantly influenced the contents of total protein (TP), albumin (ALB), globulin (GLB) and triglycerides (TG) in serum (P<0.05). The contents of TG in serum of groups supplemented with 100, 150 and 200 mg/kg vitamin E was significantly lower than that of control group (P<0.05), while the content of GLB in serum was significantly higher than that of control group (P<0.05). These results indicate that adding vitamin E to the diet can increase the growth performance, fat digestibility and antioxidant ability, as well as reduce the content of TG in serum of blue foxes during growing period. Under the conditions of this experiment, considering the cost of breeding and the growing performance of blue foxes, the supplemental level of vitamin E in the diet of blue foxes during growing period is recommended to be 100 to 150 mg/kg.