The use of cottonseed hulls as a feed resource is constrained by their high fiber content and residual free gossypol. This study evaluated the effects of steam explosion combined with fermentation using a microbial–enzyme preparation on the nutrient composition, fermentation quality, bacterial communities, and in vitro digestion and fermentation characteristics of cottonseed hulls. Four treatments were evaluated using physicochemical analyses, 16S rRNA gene sequencing, and in vitro incubation: an untreated control (CK), steam explosion (BP), fermentation with a microbial–enzyme preparation (FJ), and steam explosion followed by fermentation with the same preparation (BF). All processing treatments significantly reduced free gossypol content (p < 0.05), with BF showing the lowest concentration (70.42 mg/kg), representing a 77.89% reduction relative to CK. The neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents of BF were 573.38 and 446.23 g/kg dry matter (DM), respectively, both significantly lower than those of CK (p < 0.05) but not significantly different from those of BP. Crude protein content did not differ significantly among treatments. BF had the highest lactic acid content (27.94 g/kg DM) and the lowest endpoint pH (4.12). Bacterial community analysis showed that Firmicutes was the dominant phylum in all three fermented groups. At the end of fermentation, Lentilactobacillus was the dominant genus in the BF group, with a relative abundance of 97.55%. No associations between bacterial taxa and fermentation parameters remained significant after correction for multiple testing. KEGG functional prediction indicated differences in potential functional composition among treatments. In vitro DM digestibility in BF reached 43.99% at 48 h; however, NDF digestibility did not differ significantly among treatments at any incubation time. Cumulative gas production and total volatile fatty acid concentration in BF at 48 h were 154.28 mL/g DM and 64.58 mmol/L, respectively, neither of which differed significantly from FJ. In conclusion, steam explosion combined with microbial–enzyme fermentation reduced free gossypol content, promoted lactic acid accumulation, and altered bacterial community composition, providing experimental evidence to support further development of cottonseed hulls as a feed resource.

Camel milk is highly favored by consumers for its high nutritional value and health benefits in preventing various diseases. However, camel farming is still mainly extensive, making it difficult to control the quality of camel milk. This experiment investigated the effects of adding sodium diacetate and kojimabase, feed additives, on the quality of camel milk from lactating Bactrian camels. The results of this experiment show that adding sodium diacetate can effectively increase the content of vitamin E and vitamin C in camel milk and can also effectively increase the content of unsaturated fatty acids in camel milk, thus effectively improving the nutritional quality of camel milk. The fecal microbial analysis results showed that there was no significant impact on the microbial community among the groups, but the addition of SDA significantly increased the number of Melanocarpus fungi. This demonstrates that adding 1000 mg of sodium diacetate per kilogram to the camel diet can effectively improve the quality of camel milk, providing a technical reference and demonstration for stabilizing camel milk quality through nutritional regulation.

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.