In this study, we examined the effect of xylooligosaccharide (XOS) supplementation on the growth performance, carcass characteristics, and meat quality of Hu lambs. In total, 60 Hu lambs (two months old and weighing 17.32 ± 0.81 kg) were randomly assigned to four treatment groups, each with three replicates and five lambs per replicate. The lambs were fed basal diets supplemented with 0, 1.5, 3, or 4.5 g/kg XOSs in a basal diet for 60 days, with the groups designated XOS0%, XOS1.5%, XOS3%, and XOS4.5%, respectively. The results revealed, compared to theXOS0% group, the XOS3% group presented a lower F:G during 31 to 45 d (p = 0.06). By the 60th day, the body length indices of groups XOS3% and XOS4.5% increased compared to the XOS0% group, with a significant increase observed in group XOS4.5% (p < 0.05). Additionally, the GR values of the XOS1.5%, XOS3%, and XOS4.5% groups increased significantly, and the rumen fluid pH values of the XOS3% and XOS4.5% groups increased significantly (p < 0.01). The crude fat content in the XOS1.5% and XOS4.5% groups were significantly lower (p < 0.05). The hardness, adhesiveness, elasticity, cohesiveness, and chewiness of the mutton in the XOS1.5%, XOS3%, and XOS4.5% groups were increased, although the differences were not statistically significant (p > 0.05). Correlation analysis indicates that there is a significant correlation between growth performance, carcass traits, and meat quality (p < 0.05). The factors influencing meat quality originate from the growth period and the slaughtering phase, which can be attributed to the effects of xylooligosaccharides. In conclusion, XOS had positive effects on the growth performance, carcass characteristics, and meat quality of Hu lambs. The comprehensive effect of group XOS3% was best. Considering the production cost, the 3 g/kg XOSs is identified as the optimal supplementation level for sheep.

In the western Henan agricultural area, Duhu (Dupo♂ × Hu sheep♀) hybrid lambs are the primary breed of local meat sheep, predominantly raised in large-scale indoor feeding systems, although many farmers still rely on grazing. However, limited research exists on the meat quality of Duhu lambs under both grazing and indoor feeding systems. This study examined how grazing and indoor feeding affect the nutritional quality, flavor, amino acid profile, and fatty acid composition of 7-month-old Duhu lamb meat. Grazed lamb meat exhibited significantly (p < 0.05) higher moisture, protein content, hardness, adhesiveness, springiness, rubberiness, chewiness, and resilience than indoor-fed lamb. Regarding aroma, ammonia, oxidized compounds, and inorganic sulfides were more pronounced and stable in grazed lamb meat. Flavor analysis showed stronger bitter, salty, and sweet profiles in grazed lamb meat, whereas the sour flavor was more pronounced in indoor-fed meat. Among the volatile flavor compounds, 26 organic compounds were identified in grazed lamb meat compared with 12 in indoor-fed meat, with 1 compound common. Additionally, 16 amino acids were found in both feeding systems, with amino acid levels significantly higher (p < 0.01) in indoor-fed lamb. In total, 25 fatty acids were detected in grazed lamb meat, whereas 15 were found in indoor-fed meat, with 11 showing significantly different levels (p < 0.05). Indoor-fed lamb meat exhibited a considerably higher saturated fatty acid content (p < 0.05) compared to grazed lamb meat, while the n-3 polyunsaturated fatty acid content was significantly lower (p < 0.05).

Background: Circular RNAs (circRNAs), a novel class of endogenous non-coding RNAs with covalently closed loop structures, play important role in mammalian growth and development by regulating gene expression and participating in various biological processes. The aim of this study was to identify the expression profiles of circRNAs in the ovaries of Hu sheep and local Fat-tailed sheep during the luteal phase to determine the molecular mechanisms underlying the effects of circRNAs on reproduction and follicular development in sheep. Methods: To identify the differentially expressed circRNAs expressed in luteal phase conditions in Hu sheep and fat-tailed sheep, ovarian samples collected during the luteal phase were analyzed using high-throughput sequencing and subsequent transcriptomic approaches and bioinformatics analysis. Result: A total of 2,875 differentially expressed circRNAs were identified by high-through sequencing. Gene Ontology terminology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis showed that the host genes were mainly involved in the secretion and metabolism of the various pathway. Quantitative real-time PCR was performed to validate the results of expression profiling. These results contributed to an improved understanding of circRNA and the biological mechanisms of ovarian reproduction in sheep.