Diet supplemented with fermented onion improves growth performance, health, meat quality, and rumen metabolite profiles in Liangshan black sheep

wang sheng Jiang¹Chaoyun Yang²chen Ji³chao Li²gang Lv⁴wei hong Gao⁴Wei Zhang⁵yi Zhang^2*Zengwen Huang^2,4*

• ¹College of Animal Science; Key Laboratory of Local Characteristic Goat at Xichang University of Sichuan Province, Xichang University, Xichang, China
• ²College of Animal Science, Xichang University, Xichang, China
• ³College of Agricultural Science, Xichang University, Xichang, China
• ⁴Xinjiang Taikun Group Co., Ltd., Changji, China
• ⁵Xinjiang Agricultural Vocational and Technical University, Changji, China

This study aims to investigate the effect of fermented onion on Liangshan black sheep's growth performance, health, meat quality, and rumen metabolite profiles. A total of 80 four-month-old female Liangshan black sheep were randomly divided into 4 groups of 5 replicate pens (4 sheep per pen). Sheep were fed a basal diet supplemented with 0 (control), 10%, 20% or 30% fermented onion. Compared to that of the control group, dietary supplementation with 20% fermented onion improved final body weight, ADG and ADFI; enhanced GPT and GOT activities and increased IgA, IgG, IgM, C3 and C4 levels; increased the levels of IL-4, IL-10, TGF-β and decreased the levels of IL-1β, IL-6, TNF-α, IFN-γ; decreased MDA level and increased SOD, GST, CAT and GSH-Px activities; decrease the pH, L* value, b* value and shear force; increase the a* value and the content s of protein and fat; increase the expression levels of FN1, TGFβ1, Myf5, FAS, PPARγ and FABP4; decrease the expression levels of CPT1A and LPL. Metabolomic analysis revealed that 20% fermented onion supplementation significantly modified the metabolite profiles in the rumen liquid, with downregulated metabolites and 4 upregulated metabolites mainly enriched in purine metabolism, microbial metabolism, cutin, and suberine biosynthesis pathways. Data from our study suggest that supplementation of fermented onion to the basal diet at 20% (w/w) can be used safely to increase meat yield and to improve meat quality in the sheep industry.