Effects of copper hydroxychloride on growth performance and abundance of genes involved in lipid metabolism of growing pigs

An experiment was conducted to test the hypothesis that copper (Cu) hydroxychloride improves growth performance by upregulating the mRNA transcription of genes involved in lipid metabolism of pigs fed a diet based on corn, soybean meal (SBM), and distillers dried grains with solubles (DDGS). Thirty-two pigs (15.05 ± 0.98 kg) were allotted to 2 dietary treatments with 2 pigs per pen for a total of 8 replicate pens per treatment. Pigs were fed a corn–SBM–DDGS control diet that included Cu to meet the requirement. A second diet was formulated by adding 150 mg Cu/kg from copper hydroxychloride to the control diet. On the last day of the experiment, one pig per pen was sacrificed, and samples from liver, skeletal muscle, and subcutaneous adipose tissue were collected to analyze relative mRNA abundance of genes involved in lipid metabolism. Results indicated that overall ADG and G:F were greater (P < 0.05) for pigs fed the diet containing copper hydroxychloride compared with pigs fed the control diet. Pigs fed the diet supplemented with copper hydroxychloride also had increased (P < 0.05) abundance of cluster of differentiation 36 in the liver and increased (P < 0.05) abundance of fatty acid-binding protein 4 and lipoprotein lipase in subcutaneous adipose tissue. Inclusion of copper hydroxychloride also tended to increase (P < 0.10) the abundance of fatty acid-binding protein 1, peroxisome proliferator-activated receptor α, and carnitine palmitoyltransferase 1B in the liver, skeletal muscle, and subcutaneous adipose tissue, respectively. This indicates that dietary Cu may affect signaling pathways associated with lipid metabolism by improving the uptake, transport, and utilization of fatty acids. In conclusion, supplementation of copper hydroxychloride to the control diet improved growth performance and upregulated the abundance of some genes involved in postabsorptive metabolism of lipids.