Effects of Dietary Glycerol,Vitamin C and Niacinamide Supplementation on Liver of Growing-Finishing Pigs

Wenchen Sun^1,2Linglan Deng^1,2Wanjie Zou^1,2Panting Wei^1,2Shaobin Hao^1,2Huadong Wu²Wei Lu^1,2Yuyong He^1,2*

• ¹Key Laboratory of Animal Nutrition, Jiangxi Agricultural University, Nanchang, China
• ²College of Animal Science and Technology,Jiangxi Agricultural University, Nanchang, China

The influence of supplementing glycerol, vitamin C and niacinamide on the liver of growing-finishing pigs has not yet been examined. This study investigated the effect of 10% glycerol, 0.06% vitamin C and 0.05% niacinamide supplementation at single or combination on liver of growing-finishing pigs. Compared with pigs supplemented with 0% glycerol, 0% vitamin C and 0% niacinamide, pigs supplemented only with 10% glycerol had higher (p < 0.05) TNF-α concentration, partially hepatic steatosis, higher (p < 0.05) relative abundances of Escherichia_shigella, Prevotellaceae_UCG_003, Lachnospiraceae_XPB1014_group, Coprococcus, Lactococcus and Megamonas, lower (p < 0.05) solute carrier family 7 member 11 (SLC7A11) expression in liver tissue. However, pigs offered the diet with a mixture of 0.06% vitamin C and 0.05% niacinamide had higher (p < 0.05) relative abundance of Faecalibaculum and expression of SLC7A11, lower (p < 0.05) relative abundances of Staphylococcus and Clostridium_sensu_stricto_1 in liver tissue. Supplementation of 10% glycerol, 0.06% vitamin C and 0.05% niacinamide simultaneously to pigs increased (p < 0.05) the ferrous ion level, the relative abundances of Escherichia_Shigella, Lactococcus and Desulfobacterota, the expressions of gene Cryptochrome-1(CRY1) and SLC7A11, but decreased (p < 0.05) the expressions of gene C-reactive protein (CRP) and galactokinase 1 (GALK1) in liver tissue. Supplementation with 0.06% vitamin C and 0.05% niacinamide can alleviate the damage in liver of pigs fed a diet containing 10% glycerol.Glycerol addition can enhance food palatability(9, 10) as well as provide energy (11). It is reported that the metabolism of glycerol largely occurs in liver and it can induce anatomical, physiological, and biochemical changes in the liver when glycerol is included in the food (12,13). Currently glycerol is one of the most promising ingredients in formulating the diet of animals, owing to it can be used as an alternative energy source to corn in the diet (14), and also some studies reported that inclusion of glycerol to the diet can improve animal performance, meat quality and gut health by sparing the catabolism of dietary amino acids (15-17). However, information about the effect of long-term glycerol intake on the liver of animals is scarce.