Frontiers in Veterinary Science (Feb 2022)
Effects of Different Supplemental Levels of Eucommia ulmoides Leaf Extract in the Diet on Carcass Traits and Lipid Metabolism in Growing–Finishing Pigs
Abstract
This study examined the effects of dietary Eucommia ulmoides leaf extract (ELE) supplements on carcass traits and lipid metabolism in growing–finishing pigs. A total of 144 crossbred (Duroc × Landrace × Yorkshire) piglets with an average initial weight of 10.11 ± 0.03 kg were randomly allotted to four treatment groups, each with six replicates and six piglets per replicate. Each group of pigs was fed a basal diet or a diet supplemented with increasing levels of ELE (0.1, 0.2, or 0.3%). The results showed that adding ELE had no negative effect on the growth performance of pigs. Dietary supplements of 0.1% ELE significantly increased carcass weight (p < 0.01), dressing percentage (p < 0.01), carcass length (p < 0.05), and eye muscle area (p < 0.05). Compared with the control group, a 0.2% ELE supplement significantly increased (p < 0.01) the levels of adiponectin, insulin-like growth factor 1, and hormone-sensitive lipase and lipoprotein lipase activity in the serum. Histological examination showed that ELE inhibited fat deposition in the backfat tissue. Lipid metabolism-related biochemical indices and mRNA expression levels were improved after supplementing diets with ELE. Moreover, all three levels of ELE dramatically upregulated (p < 0.05) the protein levels of p-AMPK-α and p-ACC. In summary, adding ELE to pig diets could improve the carcass traits of growing–finishing pigs and exert a lipid-lowering effect by activating the AMPK-ACC pathway and regulating mRNA expression levels related to lipid metabolism. Supplementing the diet with 0.1–0.2% ELE is the optimal range to reduce fat deposition in pig backfat tissue.
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