This study investigated the effects of bacterial inoculants and enzyme-based silage cocktails on the dynamics of fermentation, microbiome, and nutritional value of silages produced from low-quality biomasses of reed, rice, and corn straw. A 90-day ensiling trial was performed using five distinct combinations of six basal bacterial species (Lactobacillus plantarum, Lactobacillus buchneri, Pediococcus pentosaceus, Aspergillus niger, Bacillus subtilis, and Candida utilis) and three basal enzymes (xylanase, β-mannanase, and glucanase). Each type of biomass was ensiled with six different treatments, including the Control treatment without an ensiling agent, the basal silage cocktail treatment (Mesa), and Mesa with a double dose of A. niger (MesaA), B. subtilis (MesaB), C. utilis (MesaC) and glucanase (MesaG). The “Mesa” contained (per kg silage), 1.0 × 10⁶ CFU of L. plantarum, 1.4 × 10⁷ CFU L. buchneri, 3.0 × 10⁵ CFU P. pentosaceus, 8.0 × 10⁸ CFU A. niger, 1.6 × 10⁶ CFU B. subtilis and 1.0 × 10⁹ CFU C. utilis, three enzymes (5.0 × 10⁴ U xylanase, 2.5 × 10³ U β-mannanase, and 1.0 × 10⁴ U glucanase), and 20 mL molasses. Addition of the silage cocktails significantly improved the fermentation and nutritional quality of the reed, corn, and rice straw silages. Notably, the silage cocktails increased (P < 0.01) the contents of crude protein (CP), ether extract (EE), gross energy (GE), lactic acid (LA), ratio of LA to total acids and ensiling comprehensive evaluation scores, and decreased (P < 0.01) the contents of neutral detergent fiber (NDF), acid detergent fiber (ADF) and pH of reed, corn, and rice straw silages. Regarding the silage microbiome, silage cocktails decreased the relative abundance of Enterobacter and Rahnella1, and increased the relative abundance of Leuconostoc. A. niger, and B. subtilis had a strong positive correlation with CP, EE, GE and Lactobacillus, and a negative correlation with pH, Rhizobium, and Rahnella1 in reed, corn and rice straw silages. In comparison, C. utilis had a strong positive correlation with EE, and a negative correlation with pH, Rhizobium, Stenotrophomonas, and Rahnella1. Glucanase was positively correlated with LA, EE and GE, and negatively correlated with pH and Rahnella1. Silage quality characteristics and microbiome did not differ (P > 0.05) due to the composition of silage cocktails. Based on the comprehensive membership function analysis, the silage comprehensive evaluation scores were highest for double doses of B. subtilis and glucanase for reed, corn, and rice straw. This study revealed that silage cocktails upgraded straw silage fermentation and nutritional quality, and provided a practical solution for the optimal utilization of low-quality straw biomass. Graphical Abstract

Sugarcane (Saccharum officinarum) bagasse (SCB) is one of the most widely produced lignocellulosic biomasses and has great potential to be recycled for sustainable food production as ruminant animal feed. However, due to severe lignification, i.e., lignin-(hemi)-cellulose complexes, ruminants can only ferment a minor fraction of the polysaccharides trapped in such recalcitrant lignocellulosic biomasses. This study was therefore designed to systematically evaluate the improvement in nutritional value, the in vitro dry matter digestibility (IVDMD), and the rate and extent of in vitro total gas (IVGP) and methane (CH₄) production during the 72 h in vitro ruminal fermentation of SCB, bioprocessed with Agaricus bisporus, Pleurotus djamor, Calocybe indica and Pleurotus ostreatus under solid-state fermentation (SSF) for 0, 21 and 56 days. The contents of neutral detergent fiber, lignin, hemicellulose and CH₄ production (% of IVGP) decreased (p < 0.05), whereas crude protein (CP), IVDMD and total IVGP increased (p < 0.05) after the treatment of SCB for 21 and 56 days with all white-rot fungi (WRF) species. The greatest (p < 0.05) improvement in CP (104.1%), IVDMD (38.8%) and IVGP (49.24%) and the greatest (p < 0.05) reduction in lignin (49.3%) and CH₄ (23.2%) fractions in total IVGP were recorded for SCB treated with C. indica for 56 days. Notably, C. indica degraded more than (p < 0.05) lignin and caused greater (p < 0.05) improvement in IVDMD than those recorded for other WRF species after 56 days. The increase in IVGP was strongly associated with lignin degradation (R² = 0.72) and a decrease in the lignin-to-cellulose ratio (R² = 0.95) during the bioprocessing of SCB. Our results demonstrated that treatment of SCB with (selective) lignin-degrading WRF can improve the nutritional value and digestibility of SCB, and C. indica presents excellent prospects for the rapid, selective and more extensive degradation of lignin and, as such, for the improvement in nutritional value and digestibility of SCB for ruminant nutrition.

Introduction: Abrupt weaning is a major stressful event, contributing to intestinal abnormalities and immune system dysfunction in weaned kids. Inulin is a prebiotic fiber with many positive functions, including promoting intestinal fermentation and enhancing host immunity in monogastric animals. However, the effects of a high-inulin, energy-rich diet on ruminal fermentation characteristics, methane emission, growth performance, and immune systems of weaned kids have not been investigated.Methods: A fully automated in vitro fermentation system was used to investigate ruminal fermentation characteristics and methane emission of a mixed substrate of inulin and fat powder (1.31: 1) in comparison with maize grain-based starter concentrate. During a 1-week adaptation and 4-week trial phase, 18 weaned kids (8.97 ± 0.19 kg) were randomly assigned to two groups, one with a conventional diet (83% maize grain; CON) and the other with a low-carbon, high-inulin diet (41.5% maize grain, 14.4% fat powder, 18.9% inulin; INU).Results: In the in vitro rumen fermentation experiment, the total gas production was not different (p > 0.05); however, a lower (p < 0.05) methane production was observed for INU as compared to CON. The average daily gain and the ratio of feed intake and growth performance of kids fed with INU were higher (p < 0.05) than those fed with CON. Serum concentrations of alanine transaminase (ALT) and lactate dehydrogenase (LDH) were lower (p < 0.05), whereas the concentration of high-density lipoprotein (HDL) and cholesterol (CHOL) were higher (p < 0.05) in kids fed with the INU diet as compared CON. Dietary inulin significantly increased (p < 0.05) the secretion of immunoglobulins (IgA, IgG, and IgM) and inflammatory cytokines (IFN-γ and IL-10) in ileum tissue. Although no differences (p > 0.05) were observed in mRNA expression of tight junction markers, the INU diet tended to increase (p = 0.09) gene expression of ribosomal protein S6 kinase beta-1 (P70S6K) in the mammalian target of rapamycin (mTOR) pathway of longissimus dorsi muscle.Conclusion: Our findings highlighted that a low-carbon high-inulin energy-rich diet could be used as a promising strategy to improve gut immunity and growth performance of weaned kids under abrupt weaning stress and reduce methane production.

Weaning goats are susceptible to diarrhea and have weakened immune functions due to physiological, dietary and environmental stresses. Astragalus membranaceus (A. membranaceus), a traditional Chinese medicinal herb, has been shown to improve growth performance and immunity in weaned ruminants. However, the influence mechanism of A. membranaceus on intestinal microbiota and mucosal immunity in weaned goats is still unknown. This study investigated the effects of ultra-grinded A. membranaceus (UGAM) on the immune function and microbial community in the ileum of weaned goats. Eighteen healthy weaned Xiangdong black goats (BW, 5.30 ± 1.388 kg) were used in a study of completely randomized block design with 28 days long. The animals were randomly assigned to either a basal diet supplemented with 10 g/d of milk replacer (CON, n = 9) or the CON diet supplemented with 10 g/head UGAM (UGAM, n = 9). Supplementation of UGAM increased (p < 0.05) the plasma concentrations of total protein and albumin. Meanwhile, the addition of UGAM reduced (p < 0.05) the relative mRNA expression of the IL-6 gene (a marker of inflammation), indicating the potential immunomodulatory effect of UGAM. Moreover, the relative abundances of Verrucomicrobiota and Mycoplasma were lower (p < 0.05) in the ileum of goats supplemented with UGAM than CON. These findings suggest that dietary supplementation of UGAM may have enhanced the ileum health of weaned goats by reducing inflammation factor expression and reducing the relative abundance of pathogenic microbes. The observed beneficial effects of ultra-grinded A. membranaceus on ileal mucosal immune and the community of ileal microbiota indicate its potential to be used as a viable option for promoting the well-being of weaned goats under weaning stress.

Current research is still striving to maximize the expansion of protein feed sources in order to reduce the production costs of the livestock industry. In this context, the current study aimed to evaluate the impacts of replacing soybean meal protein in diets with mulberry silage (at 50 and 100% substitution levels) on the growth, health status, and carcass characteristics of growing goat kids. Forty-five Xiangdong black goat kids weighing 18.2 ± 1.6 kg (approximately 6 months old) were divided into three experimental groups and fed one of the following diets: a control diet consisting of a 50:50 concentrate-to-roughage ratio on a dry matter basis (control), a diet replacing 50% of soybean meal protein with mulberry silage (MS-50), or a diet replacing 100% of soybean meal protein with mulberry silage (MS-100). The results show that replacing soybean meal protein with mulberry silage significantly increased (p < 0.05) the intakes of dry matter (DMI), crude protein (CPI), neutral detergent fiber (NDFI), and organic matter (OMI). However, no significant (p > 0.05) differences were observed in the digestibility of dry matter (DM), crude protein (CP), ether extract (EE), or neutral detergent fiber (NDF) among the groups, whereas the digestibility of OM and acid detergent fiber (ADF) was significantly reduced (p < 0.05) in the MS-100 group. Additionally, the MS-100 group exhibited significantly higher (p < 0.05) plasma total protein, albumin, and calcium levels. Total antioxidant capacity (TAC) was significantly enhanced in both the MS-50 and MS-100 groups compared to the control, although the MS-100 showed a significant increase (p < 0.05) in malondialdehyde (MDA) levels related to the other groups. In terms of growth performance, the MS-100 group improved (p < 0.05) final body weight, average daily gain, and carcass weights. Meanwhile, the MS-50 group recorded the highest contents (p < 0.05) of the following amino acids: aspartic acid, threonine, serine, glutamic acid, alanine, lysine, and proline. Overall, the results of the present study indicate that replacing soybean meal protein with mulberry silage generally produced comparable impacts, with additional positive effects on growth performance, meat quality, and health status of goats.