| This study was composed of three experiments. The experiment was conducted to evaluate the effects of Bacillus subtilis and Enterococcus faecium supplementations on growth performance, nutrient digestibility, immune function and pelt quality of Blue Foxes.Experiment I was conducted to study the effects of Bacillus subtilis and enterococcus faecium additives on growth performance, nutrient digestibility and nitrogen metabolism of growing blue foxes. Eighty-four foxes at the age of55days were randomly assigned into7groups with12replicates per group and1fox per replicate. The control group was fed a basal diet, and the experimental groups (groups Ⅱ、Ⅲ、Ⅳ) were fed the experimental diet which were added separately with1×108,1×109,1x1010CFU/kg of Bacillus subtilis in basal diet, while the experimental groups (groups Ⅴ、Ⅵ、Ⅶ) were fed the experimental diet which were added separately with1×108、1×109、1×1010CFU/kg of Enterococcus faecium in basal diet. The adaptation period lasted for7days and the formal period lasted for56days. The results showed that:group Ⅲ、Ⅳ、Ⅴ were significantly higher than the control group (P<0.05) in the average daily gain. Group Ⅲ、Ⅳ were significantly lower than the control group in the feed to gain (P<0.05). The output of dry matter in group Ⅲ、Ⅳ、Ⅴ were significantly lower than the control group (P<0.05). The digestibility of dry matter, protein in group Ⅲ、Ⅳ、Ⅴ was significantly higher than the control group (P<0.05). Group Ⅲ and Ⅳ were significantly higher than the control group and group Ⅵ and Ⅶ in the digestibility of crude fat (P<0.01), while it was significantly higher than group Ⅱ (P<0.05). The nitrogen deposition in group Ⅵ, Ⅶ was significantly lower than the control group (P<0.05),except for that all the experimental groups are higher than the control group. Group Ⅵ Ⅶ are significantly lower than the control group (P<0.05) and group Ⅱ、Ⅲ、 Ⅳ、Ⅴ(P<0.01) in net protein utilization and the biological value of protein. In conclusion, the nutrient digestibility, nitrogen deposition, net protein utilization, and biological value of protein are ideal when add1×10CFU/kg Bacillus subtilis in diet and the blue foxes can get the optimal growth performance. When add1×108CFU/kg enterococcus faecium in diet, blue foxes can gain better growth performance and higher nutrient digestibility. Experiment Ⅱ was conducted to study the effects of Bacillus subtilis and enterococcus faecium additives on immune function of growing blue foxes. Eighty-four he oxes at the age of55days were randomly assigned into7groups with12replicates per group and1fox per replicate. The control group was fed a basal diet, and the experimental groups were fed the experimental diet which were added separately with1×108,1×109,1×1010CFU/kg of Bacillus subtilis and1×108、1×10、1×1010CFU/kg of Enterococcus faecium in basal diet. The adaptation period lasted for7days and the formal period lasted for56days. The results showed as follows:compare with the control group, the experimental groups which was add Bacillus subtilis was increased in total serum protein (P>0.05), while groups add with enterococcus faecium was lower than the control group (P>0.05). Group Ⅳ was significantly higher than group Ⅵ in total protein (P<0.05). The globin in group Ⅲ and Ⅵ are significantly higher than the control group (P<0.05), there are no difference between other groups (P>0.05). The difference of IgG and IgM in serum of each group was not significant (P>0.05). group Ⅳ was significantly higher than the control group and group Ⅶ in IgA (P<0.05), while group V was higher than group VII too (P<0.05). In conclusion, the immune function was improved in blue foxes when fed the experimental diet supplemented with1×1010CFU/kg Bacillus subtilis or1×108CFU/kg enterococcus faecium.Experiment Ⅲ was conducted to study the effects of Bacillus subtilis and Enterococcus faecium additives on growth performance, nutrient digestibility and pelt quality of blue foxes during winter hair period. Eighty-four healthy blue foxes at the age of25weeks were randomly assigned into7groups with12replicates per group and1fox per replicate. The control group was fed a basal diet, and the experimental groups were fed the experimental diet which were added separately with1×108,1×109,1×1010CFU/kg of Bacillus subtilis and1×107,1×108,1×109CFU/kg of Enterococcus faecium in basal diet. The pre-test lasted for7days and the trial lasted for56days. The results showed as follows:The final weight in group Ⅳ was significantly higher than the group Ⅰ and group Ⅶ (P<0.05). The average daily gain in group Ⅳ and Ⅴ were significantly higher than the group Ⅰ, Ⅲ and Ⅶ (P<0.05), while there is no significant difference among each groups of the average feed gain and F/G (P>0.05). The digestibility of dry matter in group Ⅶ was significantly lower than the other groups (P<0.01). The digestibility of dry matter in group Ⅳ was significantly higher than the group Ⅰ (P<0.05). The digestibility of protein in group Ⅳ was significantly higher than the group Ⅰ, Ⅱ and Ⅶ (P<0.05). Group Ⅴ and Ⅵ were significantly higher than the group Ⅰ, Ⅱ and Ⅲ in the digestibility of fat (P<0.05), The nitrogen deposition in group VI was significantly higher than the group I, II and VII (P<0.05), The under fur length in group IV and V was significantly higher than the group I (P<0.05). There is no differences between the control group and the experimental groups in body length, guard fur length, under fur abundance and fur glossiness (P<0.05). In conclusion, adding1×1010CFU/kg Bacillus subtilis or adding1×107CFU/kg Enterococcus faecium in diet of blue foxes during winter hair period, can improve the average daily gain, the final weight, the digestibility of protein and the digestibility of fat, it also can reduce the fecal nitrogen excretion, increasing nitrogen deposition. It can obtain the better fur quality as well. |
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