Numerous studies have demonstrated that Broussonetia papyrifera is an unconventional feed resource with significant developmental potential. This research aimed to explore the effects of Broussonetia papyrifera silage on the growth performance, blood parameters, immunity, antioxidation, cytokine levels, and rumen bacterial composition of Kazakh lamb. Forty healthy male Kazakh lambs, aged 5 months and weighing 30.12 ± 1.14 kg, were randomly divided into control and experimental groups, each consisting of four replicates (five lambs per replicate). The control group was fed a basal diet, while the experimental group received a diet supplemented with 20% Broussonetia papyrifera silage (dry matter basis). Following a 10-day pre-feeding period, a 60-day formal experiment was conducted. The results indicated no significant difference in growth performance between the experimental and control groups. However, compared to the control group, the use of Broussonetia papyrifera silage significantly reduced (p < 0.05) neutrophil, lymphocyte, and eosinophil counts, as well as creatinine levels in the blood. Furthermore, Broussonetia papyrifera silage (p < 0.01) enhanced total serum antioxidant capacity, superoxide dismutase, catalase, glutathione peroxidase, immunoglobulin A, immunoglobulin M, immunoglobulin G, interleukin-2, interleukin-6, and interleukin-8, and decreased malondialdehyde and interleukin-4 levels. Additionally, the use of Broussonetia papyrifera silage increased the diversity and richness of the rumen bacterial community, notably enhancing the relative abundance of Firmicutes such as Rikenellaceae_RC9_gut_group and Christensenellaceae_R-7_group. In conclusion, feeding Kazakh lamb with Broussonetia papyrifera silage (20% DM) did not adversely affect their growth performance but improved their immunity and antioxidant capacity and enhanced the relative abundance of beneficial bacteria in the rumen, thereby promoting animal health.

Lactic acid bacteria (LAB) and cellulase have been used as additives to improve the fermentation quality of mulberry silage. This study investigated the dynamics of fermentation characteristics and bacterial communities during 60-day ensiling through three established treatment groups: Control (no inoculation), Lactiplantibacillus plantarum (LP) inoculation as well as combination of L. plantarum and cellulase inoculation group (LPC). The results showed that compared with the Control group, the LP and LPC treatments significantly reduced the loss of dry matter, soluble carbohydrates, and crude protein (p < 0.05), effectively promoted the accumulation of lactic acid and acetic acid (p < 0.05), but significantly elevated ammonia nitrogen (NH₃-N) production. Inoculation was beneficial to the stability of the bacterial community in mulberry branch and leaf silage because it can maintain a high level of beneficial bacteria (Lactiplantibacillus) and inhibit the growth of harmful bacteria (Escherichia-Shigella). The combination of the inoculation of L. plantarum and cellulase may improve the quality of mulberry branch silage.

Paper mulberry (Broussonetia papyrifera) is a high-protein forage, but its high buffering capacity and low water-soluble carbohydrate (WSC) content hinder silage fermentation. This study evaluated the effect of tea tree (Melaleuca alternifolia) essential oil (TTO) as a natural additive for paper mulberry silage. TTO was added at 0 (CK), 500 (CSD), and 1000 mg/kg (CSG) fresh weight, with samples collected on days 7, 15, 30, and 90. After 90 days, CSD had the lowest pH and the highest lactic acid content. NH₃-N/TN was significantly lower than in CK (p < 0.05), and the retention of dry matter, crude protein and water-soluble carbohydrate was improved (p < 0.05). Compared with CK, CSD exhibited the highest lactic acid bacteria (LAB) counts, along with the lowest mold and aerobic bacterial counts (p < 0.05). However, CSG did not further improve fermentation quality, and most of the indicators were not significantly different from CSD (p > 0.05). The in vitro gas production test showed that CSD significantly increased the theoretical maximum gas production and the maximum gas production rate (p < 0.05). Additionally, 16S rRNA sequencing revealed a distinct bacterial succession in CSD, which enriched beneficial lactic acid bacteria (LAB) such as Pediococcus while outcompeting less competitive taxa. This microbial reshaping redirected the community toward acidification and nutrient retention. Collectively, these results demonstrate that TTO at 500 mg/kg is a promising natural additive for improving paper mulberry silage quality through selective reshaping of the bacterial community.