Effect Of Dietary Copper Levels On Liver Copper Transport In Sheep

The experiment was conducted to investigate the effect of copper on growth performance, blood biochemical parameters, effect of liver copper and copper concentration in blood and liver subcellular damage and liver copper transporter associated factor m RNA expression in liver of sheep.It was the theory basis for further study of copper metabolism of different speciesEffects of dietary copper levels on the production performance of sheep. In the experiment, 15 sheep were randomly assigned to 3 groups(5 replicates with 1 sheep in each replicate). Each group was Cu0 group(based on the diet of no additional copper), Cu10 group(based on the addition of 10 mg Cu/kg DM) and Cu25 group(based on the addition of 25 mg Cu/kg DM). At the end of the experiment, the average daily gain(P>0.05) and feed conversion rate(P>0.05) were increased by the addition of 10mg/kg sulfate,which could significantly increase the average daily feed intake(P<0.05). Supplementing 25mg/kg could reduce the average daily gain(P>0.05) and feed conversion ratio(P>0.05) of sheep,which could significantly reduce the average daily feed intake(P<0.05). The results showed that the Cu10 group in the experiment could promote the growth of the sheep, and the Cu25 group had a negative effect on the performance of the sheep.Effect of dietary copper levels on serum biochemical parameters and liver copper content in sheep. The serum samples were respectively collected from the 0d, 30 d and 60 d. The blood indexes of the liver damage, the copper enzyme, the copper content in the serum and in liver were measured respectively. The results showed that the 30 day trial period, diets adding 10 mg / kg copper sulfate can significantly improve the serum copper zinc superoxide discrimination of enzyme and ceruloplasmin activity(P<0.05). Copper zinc superoxide dismutase and total bilirubin(P<0.05) in serum was significantly increased by the addition of 25mg/kg sulfate. The activity of Cu-Zn SOD in serum of Cu25 group was significantly higher than that in Cu10 group(P<0.05).The supplementation of Cu did not have effect on alanine transaminase, aspartate aminotransferase, alkaline phosphatase activity and total protein, albumin content(P > 0.05). In the 60 day trial period, adding 10 mg / kg copper sulfate can significantly improve the serum copper zinc superoxide discrimination of enzyme and ceruloplasmin activity(P < 0.05). Adding 25 mg / kg copper sulfate could significantly increase the serum alanine aminotransferase, aspartate aminotransferase, Cu-Zn superoxide dismutase, ceruloplasmin activity and total bilirubin contents(P< 0.05). Ceruloplasmin and copper zinc superoxide dismutase activity in Cu25 group were significantly higher than those in Cu10 group(P<0.05). The serum alkaline phosphatase activity and total protein and albumin levels were not significantly affected by the addition of 10mg/kg and 25mg/kg sulfate in diets( P>0.05). In 30 d and 60 d, the blood copper levels were not significantly different(P>0.05), the copper content in the liver of sheep increased significantly(P<0.05).Effect of dietary copper levels on liver ultrastructure of sheep. The test period 60 d, Cu0 group under the electron microscope had not obvious pathological changes. Adding 10 mg/kg dietary copper in liver mitochondria was irregular and elongated, and the high electron density of sedimentary body was a certain amount in the liver cytoplasm. When 25 mg / kg copper is added in the diet, liver mitochondria appeard edema and fewer, the integrity of the cell membrane and nuclear membrane were destroyed, cytoplasm appeard electron dense deposits. Cu10 group had a slight degree of injury of liver ultrastructure,and ultrastructure in Cu25 group had injury obviously.Effect of dietary copper on the relative expression level of liver copper transporter m RNA of sheep. CTR1 and CTR2 and ATP7 A m RNA relative expression quantity of copper ion concentration in sheep liver tissue firstly increased and then decreased,, Cu25 shape group expression was significantly lower than that of control group(P < 0.05). Sheep liver tissue ATP7 B m RNA expression increased with the concentration of copper ions increasing, expression in Cu10 group and Cu25 group was significantly higher than Cu0 group. The results showed that the high concentration of copper ion inhibited the expression of copper transporter, low concentration promoted the expression.