Fermented Apple Pomace Improves Plasma Biochemical and Antioxidant Indicators and Fecal Microbiota of Weaned Pigs

Abstract

As a by-product, apple pomace (AP) is very rich in pectin, polyphenols, carbohydrates and minerals, which have antioxidant and immune-enhancing functions on animals. To investigate the effects of fermented AP on pigs, a total of 120 weaned pigs were allocated into one of two treatments: the control (CON) group, fed with diets containing 5% silage AP; or the AP group, fed with diets containing 5% silage corn-AP for 28 d. The average daily gain was increased (p < 0.001) in the AP group compared with the CON group. The concentration of albumin and superoxide dismutase were increased by 8.98 g/L (p < 0.001) and 2.9 U/mL (p = 0.001), while the concentration of aspartate aminotransferase and malondialdehyde were decreased by 23.59 U/L (p < 0.001) and 2.33 nmol/mL (p = 0.003) in the AP group, respectively. There were 46 and 125 unique OTUs in the AP and CON groups, respectively. In the AP group, the abundance of Lactobacillus was increased (p < 0.003), but the abundances of Clostridium_sensu_stricto_1 (p = 0.001), Terrisporobacter (p = 0.026), Ruminococcus (p = 0.001) were decreased. In addition, the relative abundance of genetic information processing pathways was increased (p = 0.001) in the AP group, while the relative abundance of cellular processes had a tendency to decrease (p = 0.056) in the AP group. Above all, the supplementation of fermented AP has beneficial impacts on the growth, plasma biochemistry and immune indicators, and gut microbiota of weaned pigs.