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).

This study investigated the effects of dietary supplementation with xylo-oligosaccharides (XOS) on the nutritional composition, sensory characteristics, and volatile organic compounds (VOCs) of Hu sheep meat. Results indicated that XOS had no significant impact on mineral and amino acid contents. However, it significantly increased the concentrations of stearic acid (C18:0), linoleic acid (C18:2 n-6 cis), α-linolenic acid (C18:3 n-3), polyunsaturated fatty acids (PUFAs), and total n-3 fatty acids, and simultaneously decreased the n-6/n-3 ratio. Electronic nose results showed that XOS effectively attenuated “goaty” flavors associated with sulfides and putrid off-odors linked to nitrogenous compounds. Meanwhile, electronic tongue analysis revealed that XOS reduced bitterness perception, which was closely correlated with alterations in volatile flavor compounds. A total of 30 volatile compounds were identified by GC-MS analysis, and nonanal was identified as a key odor-active compound (VIP > 1, ROAV > 1). In this study, nonanal added some new grassy and fatty notes, which made the sense of freshness stronger. In summary, dietary XOS supplementation improved nutritional value and sensory properties through the optimal fatty acid composition and modulation of the main flavor compounds and was able to provide an option for developing high-quality functional lamb products.