Copper On The Appropriate Addition And The Effect Of Fatty Metabolism Of Rex Rabbits

The purpose of this trail was to study the effect of different copper levels on the production performance,organ development,blood metabolites in serum,tissue copper retention and fatty metabolism of weaned to 3 months-old Rex rabbits.Two hundred 1 months Rex Rabbit were randomly divided into 5 treatments,40 replicates per treatment,1 rabbit per replicate.Rabbits of 5 groups were fed diets with different copper addition levels(0,5,15,45,135 mg/kg copper,respectively).The experiment lasted for 66 days comprised a7-days adaptation and 59-days data collection.The results are as follows:(1)The dietary with different copper supplement levels had significant influence on average daily gain and average daily intake(P<0.05)of weaned to 3 months old Rex rabbits.When the copper supplement was 15 mg/kg,the average daily gain and average daily intake reach the highest value.Dietary copper levels had significant influence on fur weight(P<0.05).Dietary copper levels had significant influence on drip loss and pH(P<0.05).On the whole,when the copper supplement was 15,45 mg/kg,the meat quality showed good traits.The dietary with different copper supplement levels had significant influence on intake nitrogen,fecal nitrogen,urinary nitrogen,nitrogen retention,nitrogen apparent digestibility,nitrogen utilization rate and biological value of nitrogen(P<0.05).All showed a tendency to increase first an then decrease.Dietary copper levels had significant influence on liver index(P<0.05).Dietary copper levels had extremely significant influence on TP,Alb and UREA(P<0.05).All showed a tendency to increase first an then decrease.Dietary copper levels had significantly increased intake copper,fecal copper,digestible copper and copper apparent digestibility.Dietary copper levels had significant influence on the content of copper in liver(P<0.05),and the amount of copper deposited in the liver had increased with increasing copper levels.Dietary copper levels had extremely significant influence on front leg muscle weight,front leg muscle weight,total muscle weight,front leg muscle,rate hind leg muscle rate,and total muscle rate(P<0.05),and they had reached the highest value when the copper supplement was 15 mg/kg.In conclusion,the appropriate addition of diet copper of weaned to3 months old Rex rabbits was 15-45 mg/kg.(2)According to the above indicators,we selected the group with the diet copper of 0mg/kg as the control and the group with the diet copper of 45 mg/kg as the treatment,to study the Effect of the mechanism of fatty metabolism of growing Rex rabbits.Copper treatment significantly decreased the deposition of shoulder fat,kidney fat and total fat.Copper treatment significantly inhibited cytoplasmic lipid accumulation in liver,skeletal muscle and adipose tissue(P<0.05).Compared with the control group,dietary copper addition significantly decreased very low density lipoprotein levels(P<0.05).Copper treatment significantly increased gene expression of CPT1,CPT2 and PPAR? in liver(P<0.05).In skeletal muscle,CPT1,CPT2,fatty acid transport protein,fatty acid-binding protein,and PPAR mRNA as well as phosphorylated AMP-activated protein kinase(AMPK)levels were significantly up-regulated by copper treatment(P<0.05).Rabbits receiving copper supplementation had higher CPT1,CPT2,PPAR and hormone-sensitive lipase mRNA levels in adipose tissue(P<0.05).In conclusion,copper promoted skeletal muscle growth and reduced fat accretion.PPAR signaling in liver,skeletal muscle and adipose tissues and AMPK signaling in skeletal muscle tissue were involved in the regulation of lipid metabolism by copper.