<scp>d</scp>-Aspartate in Low-Protein Diets Improves the Pork Quality by Regulating Energy and Lipid Metabolism via the Gut Microbes
Chenyu Wang, Le Huang, Shunshun Jin, Ruoxin Hou, Mingzhe Chen, Yonghui Liu, Wenjie Tang, Yuying Li, Yulong Yin, Liuqin He
Abstract
d -Aspartate is critical in maintaining hormone secretion and reproductive development in mammals. This study investigated the mechanism of different d -aspartate levels (0, 0.005, 0.05, and 0.5% d -aspartate) in low-protein diets on growth performance and meat quality by mediating the gut microbiota alteration in pigs. We found that adding 0.005% d -aspartate to a low-protein diet could dramatically improve the growth performance during the weaned and growing periods. Dietary d -aspartate with different levels markedly increased the back fat, and 0.5% d -aspartate significantly increased the redness in 24 h and reduced the shear force of the longissimus dorsi (LD) muscle. Moreover, d -aspartate treatments decreased the mRNA expression of MyHC II a and MyHC IIx in the LD muscle. The protein expression of MyH1, MyH7, TFAM, FOXO1, CAR, UCP2, and p-AMPK was upregulated by 0.005% d -aspartate. Additionally, the abundance of Alistipes, Akkermansia, and the [ Eubacterium ]_ coprostanoligenes _group in the intestinal chyme of pigs was significantly decreased by d -aspartate treatments at the genus level, which was also accompanied by a significant decrease in acetate content. These differential microorganisms were significantly correlated with meat quality characteristics. These results indicated that d -aspartate in low-protein diets could improve the growth performance and meat quality in pigs by regulating energy and lipid metabolism via the alteration of gut microbiota.