Effects of dose and duration of dietary copper administration on hepatic lipid peroxidation and ultrastructure alteration in piglets’ model

Abstract

Background: Copper is an essential microelement for animals and has been used at pharmacological doses in weaned piglets to improve growth performance. However, it also induces systemic oxidative stress after short-term feeding. The aim of this study was to investigate the effects of dose and duration of dietary copper on lipid peroxidation and oxidative stress status in model of weaned piglets. Methods: A total of 48 crossbred piglets (weaned at 21d, weight ∼8.2 kg) were randomly assigned into 4 groups of 12 in each. The control group and 3 treatment groups fed with basal diet supplemented with 20, 100 and 200 mg/kg copper as copper sulfate for 3 and 6 weeks, respectively. Results: Dietary copper supplementation significantly affected the activities of ALP, LDH, LIPC and the levels of Ca and TG in serum as well as the copper and zinc deposition in liver. Increased MDA concentrations, and decreased GPX, CP and CAT concentrations in serum were found in 0, 100 and 200 mg Cu/kg diet groups at 3 weeks post weaning. Hepatic lipid peroxidation was also induced in these groups indicated from hepatic SOD1, GPX1, CAT, CP, MT1A and MT2A transcriptional levels. Those adverse symptoms were alleviative at 6 weeks post weaning. The hepatic Cu and Zn concentrations, serum MDA concentrations, and serum CAT and GPX activities were significantly correlated with Actinobacillus, Lactobacillus, Sarcina, Helicobacter, Campylobacterales, which could affect the intestinal health further. Conclusion: These results indicated that copper deficiency or over supplementation would affect the systemic lipid peroxidation. These adverse changes were not observed when the dietary copper concentration at 20 mg Cu/kg diet. The results suggested the appropriate dietary copper concentration is around 20 mg Cu/kg diet, and its range might be much stricter than we thought.