Effects of Dietary 5′-CMP on Neu5Gc Contents in the Muscle and Viscera of Xiang Pigs

In order to reduce the health risks associated with red meat as listed by the World Health Organization, the work presented in this article aimed to elucidate the interaction between 5'-CMP-supplemented feed and N-glycolylneuraminic acid (Neu5Gc) in experimental animals in vivo. 5'-CMP was added to the diet of 90-, 180-, and 270-day-old Xiang pigs, and after 30 days, the Neu5Gc contents, physicochemical parameters, and free amino acid contents of muscle and internal viscera were measured by high-performance liquid chromatography coupled with fluorescence detection. The mechanism by which 5'-CMP affects Neu5Gc contents was investigated using molecular docking. Results show that 5'-CMP significantly decreased the Neu5Gc content in 180-day-old Xiang pigs (P < 0.05) but had no effect on the Neu5Gc contents in 90- and 270-day-old Xiang pigs. Umami amino acids were significantly increased in 180-day-old Xiang pigs. In the 90- and 270-day-old pigs, histidine increased by 10.38 and 17.87%, respectively. The other free amino acids were either reduced or not affected. Moreover, the 5'-CMPsupplemented diet did not affect the physicochemical parameters of the longissimus muscle in the Xiang pigs. 5'-CMP could occupy almost all the sialyltransferase active-site residues but not His302 and showed inhibition of the sialyltransferase activity. The results provided an experimental basis for the subsequent reduction of Neu5Gc in red meat before slaughter. HIGHLIGHTS Intervention with 5'-CMP to modify Neu5Gc contents in Xiang pigs of different ages is discussed. This study aims to discover an effective method for reducing the risk of chronic disease. The inhibition mechanism of 5'-CMP on sialyltransferase and CMAH was explored by molecular docking. The addition of 5'-CMP to feed did not affect the processed-meat characteristics of Xiang pigs. 5'-CMP provides a novel tactic for reducing Neu5Gc content in red meat before slaughter.

Automated summary

This study successfully reduced the Neu5Gc content in 180-day-old Xiang pigs by adding 5'-CMP to their feed, while increasing umami amino acids. The inhibitory mechanism and effects of 5'-CMP varied in Xiang pigs of different ages, and there was no significant impact on the physicochemical parameters of the longissimus muscle.