Effect Of Enzymes On Growth Performance And Fur Quality Of Raccoon Dogs

The purpose of this thesis is to study the effect of adding enzyme preparations to reduce the nitrogen or/and phosphorus content of the raccoon dog’s diet during the rearing period and the winter hair period on the growth performance and fur quality of the raccoon dogs,and to determine the level of enzyme preparation to be added.Low-carbon breeding of raccoon dogs provides experimental basis.Experiment 1.Effect of compound enzymes on growth performance,nutrient digestibility,nitrogen and phosphorus utilizations and serum biochemical indices of growing raccoon dogs.A total of 75 raccoon dogs(BW 3.01±0.29 kg)were randomly divided into 5 groups(15 repetitions each group,1 raccoon per repetition),and fed the control diet(normal nitrogen and phosphorus level diet,group 1),normal nitrogen and phosphorus level diet supplemented with enzyme(group 2),normal nitrogen and low phosphorus level diet supplemented with enzyme(group 3),low nitrogen and normal phosphorus level diet supplemented with enzyme(group 4),low nitrogen and phosphorus level diet supplemented with enzyme(group 5)for 58 days.The compound enzyme was composed of 500 U/kg acid protease and 1500 FTU/kg phytase.The results showed that:(1)Addition of enzymes in the diet had no significant effect on growth performance(P>0.05).(2)Addition of compound enzymes to normal diet significantly affected digestibility of crude protein and fecal nitrogen(P<0.05),in which the two indices in the enzyme-added group were significantly higher than those in the non-enzyme group(P<0.05).The digestibility of energy and crude protein in three normal nitrogen and low phosphorus groups were higher than those in the other groups(P<0.05),and the nitrogen contents in manure were lower than that in the normal diet group(P<0.05).Nitrogen emissions decreased by 13.9% and 14.0% in group 4 and 5,which were significantly lower than the control group(P<0.05).Addition of enzymes in normal diet had no significant effect on phosphorus metabolism indices(P>0.05).Addition of enzymes to low-nitrogen or low-nitrogen and low-phosphorus diets significantly affected the intake of phosphorus,fecal phosphorus and phosphorus retention(P<0.05).There were no differences between group 4 and control group in phosphorus intake and fecal phosphorus(P>0.05),but phosphorus retention is lower than control group(P<0.05).Phosphorus intake,fecal phosphorus and phosphorus retention in group 3 and 5 were significantly lower than those of control group(P<0.05).Additions of enzymes to low-phosphorus or low-nitrogen and low-phosphorus diets reduced phosphorus emissions by 29.7% and 18.1%.(3)Addition of enzymes to normal diet significantly affected AST activity(P<0.05),and the AST activities in enzyme-added groups were significantly lower than that of the control group(P<0.05).Addition of enzymes to low-nitrogen or/and low-phosphorus diets significantly affected AST activity and ALB(P<0.05),in which the AST activity of experimental groups were significantly lower than that of the control group(P<0.05),and the ALB activity group 4 was significantly higher than those in the other groups(P<0.05).Experiment 2.Effect of enzymes on growth performance,nutrient digestibility,nitrogen and phosphorus utilizations,serum biochemical indices,femoral development and fur quality of winter raccoon dogs.A total of 60 raccoon dogs(BW3.01±0.29 kg)were randomly divided into 5 groups(12 repetitions each group,1raccoon per repetition),and fed the control diet(normal nitrogen and phosphorus level diet,group 1),low nitrogen and phosphorus level diet supplemented with enzyme(group 2),normal nitrogen and low phosphorus level diet supplemented with enzyme(group 3),low nitrogen and normal phosphorus level diet supplemented with enzyme(group 4),low nitrogen and phosphorus level diet supplemented with enzyme(group 5)for 74 days.Diet in group 3 was added 1500 FTU/kg phytase,and diet in group 4 was added 500 U/kg acid protease.Diet in group 5 was added 500 U/kg acid protease and 1500 FTU/kg phytase compound enzymes,and diet in group 2 was added 2 times of the compound enzymes in group 5.The results showed that:(1)Addition compound enzyme preparation significantly affects growth performance(P<0.05).The final weight in group 5 was significantly lower than that in the other groups except for the control group(P<0.05).(2)Addition of Enzymes significantly affected the digestibility of organic matter and energy(P<0.05),in which the two indices of group 5 were significantly lower than those of the other groups(P<0.05).The digestibility of organic matter in the control group was significantly lower than that in group 4(P<0.05).The nitrogen deposition of the group 5 was significantly lower than that of the control group(P<0.05).The nitrogen emission of group 4 was reduced by 14.1%,and the nitrogen emission of the group 2 was reduced by 22.6%.There were significant differences in phosphorus intake,fecal phosphorus and phosphorus deposition among groups(P<0.05),The three indicators of test 2,3 and 4groups were significantly lower than those of the control group(P<0.05).The phosphorus emission in group 3 was reduced by 19.7%,and the phosphorus emission in the group 2 was reduced by 13.9%.(3)There were significant differences in ALP activity and calcium content among the groups(P<0.05),in which the ALP activity in group 4 and 5 were significantly higher than that in the other three groups(P<0.05),and the calcium content in group 3,4 and 5 were significantly higher than that in the other two groups(P<0.05).(4)There were no differences in all indices of femur(P>0.05).(5)There were differences among groups in shoulder width of fur(P<0.05),in which the group 5 had lower value than that in the other groups(P<0.05).The above results show that adding a compound enzyme preparation while appropriately reducing the nitrogen or/and phosphorus content in the raccoon dog’s diet during the rearing period has no significant effect on the growth performance of the raccoon dogs.It can improve the digestibility of crude protein and nitrogen emissions are reduced by more than 12.8%,and phosphorus emissions are reduced by more than 18.1%.Adding enzyme preparations while appropriately reducing the nitrogen or/and phosphorus content in the raccoon dog’s diet during the winter-hair period has no significant effect on the growth performance and fur quality of the raccoon dog.It can reduce nitrogen emissions by more than 14.1% and phosphorus emissions by more than 13.9%,which can improve the breeding environment of raccoon dogs and reduce environmental pollution.