The residual black wolfberry fruit (RBWF), rich in nutrients and active substances, has the potential to serve as an antibiotic alternative. This study evaluated the concentration-dependent effects of RBWF on serum biochemistry, immunity, antioxidant capacity, and meat quality of fattening sheep. Forty 3-month-old sheep were randomly assigned into four groups with 10 replicates in each group and fed experimental RBWF-supplemented diets (0%, 2%, 5%, and 8%). The results showed that RBWF supplementation significantly increased the serum levels of TP, BUN, ALT, AST, IgA, IgM, T-AOC, SOD, and GSH-Px in sheep (p < 0.05), while significantly decreasing the levels of LDH, TG, LDL-c, IgG, and MDA (p < 0.05). Furthermore, dietary RBWF significantly increased the VB1 and IMP levels in the longissimus dorsi muscle of sheep (p < 0.05) and significantly decreased the contents of fat and cholesterol (p < 0.05). Finally, RBWF increased the contents of C20:4 and Glu (p < 0.05). In conclusion, dietary supplementation with RBWF can improve the immune and antioxidant capacity of sheep and has a certain effect on improving the flavor of meat, of which 5% is the best.

Lycium ruthenicum leaves (LRL), as an agricultural by-product rich in bioactive compounds, can be used as an unconventional feedstuff in animal diets and have the potential to improve animal health. This study investigates the effects of dietary supplementation with graded levels of LRL on rumen fermentation, meat amino acid and fatty acid profiles, and rumen bacterial diversity in sheep. Forty three-month-old male Dorper × Hu crossbred F1 lambs with an initial body weight of 29.58 ± 2.06 kg were randomly assigned to four groups (n = 10). Over a continuous 63-day trial period, the lambs were fed diets containing 0%, 5%, 10%, and 15% LRL, respectively. At the end of the trial, rumen fluid and longissimus dorsi muscle samples were collected to assess rumen fermentation characteristics, bacterial community structure, and meat quality. The results showed that: (1) The concentrations of acetate, butyrate, and total volatile fatty acids (TVFA) in the rumen were increased in the LRL5% group (p < 0.05 or p < 0.01). (2) The relative abundance of the phylum Firmicutes and the genus Ruminococcus increased (p < 0.05), while the relative abundance of the genus Prevotella decreased (p < 0.05) in the LRL5% group. (3) Meat L* increased (p < 0.05), and a* decreased (p < 0.05) in the LRL-supplemented groups. (4) The content of sweet amino acids in meat increased in LRL groups (p < 0.05). Moreover, the contents of non-essential amino acids, sweet amino acids, and total amino acids in meat increased linearly with increasing dietary LRL levels (p < 0.05). (5) Compared with the CON group, the content of C18:0 in meat decreased in the LRL5% group (p < 0.05), while the content of C20:1 increased in the LRL10% group (p < 0.05). In conclusion, dietary supplementation with LRL can improve meat quality, rumen fermentation, and rumen bacterial community structure in sheep. The recommended dietary inclusion level of LRL ranges from 5% to 15%.

Camel milk is highly valued for its nutritional and therapeutic properties. However, extensive management systems often lead to inconsistent milk quality. This study aimed to evaluate the effects of sodium diacetate (SDA) and Aspergillus oryzae (AO) as dietary additives on the milk composition and fecal microbiota of lactating Bactrian camels. Thirty camels of similar parity were randomly assigned to three groups: a control group (TMR), an SDA group (1000 mg/kg DM), and an AO group (40 g/d). The trial lasted 45 days, including a 15-day acclimation period. Routine milk components were analyzed every 10 days, while fatty acids and fecal microbiota were assessed on day 30. Results showed that SDA supplementation significantly increased the concentrations of Vitamin E, Vitamin C, and unsaturated fatty acids (UFA) in milk without affecting milk yield or routine components. Microbiota analysis indicated that SDA treatment significantly increased the abundance of the fungal genus Melanocarpus, although no broad shifts in microbial community structure were observed across groups. In conclusion, dietary SDA (1000 mg/kg) effectively enhances bioactive substances in camel milk while maintaining stable milk quality. These findings suggest that SDA is a viable “green” additive for improving the functional value of camel milk in intensive production systems.

This study investigated the effects of dietary stevia straw supplementation on meat quality, amino acid and fatty acid content, and rumen microbial diversity in sheep. A total of 50 ram lambs (3–4 months, 27.01 ± 3.8 kg) were randomly assigned to five groups. Each group received a total mixed ration supplemented with 0% (control), 5%, 15%, 25% and 35% dry stevia straw for 72 days. Adding 15% and 25% stevia straw significantly increased the pre-slaughter body weight. EE content was also significantly higher across all experimental groups (p < 0.01), showing a linear increase with supplementation. Glutamic acid content in the 15% group was significantly higher than that in the 25% group (p < 0.05). The addition of stevia straw improved the fatty acid profile: C18:1n9c content in the 5%, 15%, and 25% groups was significantly higher than that in the CK (Control) group (p < 0.05); C18:2n6c content in the 25% group was significantly higher than that in the CK, 5%, and 15% groups (p < 0.05); the content of (C20:1) was extremely significantly higher in all experimental groups compared to the CK group. Additionally, the unsaturated fatty acid content in the 25% group was significantly higher than that in the CK group (p < 0.05). The relative abundances of Bacteroidota and Firmicutes were increased in the 25% and 35% groups, but the differences were not significant (p > 0.05). In conclusion, dietary supplementation of 15–25% stevia straw to the ration can significantly improve the slaughtering performance, meat quality and muscle nutrient composition of fattening sheep. In addition, the addition of stevia straw had no negative effect on the rumen microflora, and the 15% level could increase the abundance and activity of the rumen microflora, so it is recommended to use 15% stevia straw in the ration for sheep during the fattening period.