Jianguo Zhang

Re-ensiling is an important practice in the commercialization and transportation of high-quality silage, yet limited information is available regarding its effectiveness under different storage temperatures and aerobic exposure times. This study aimed to evaluate the effects of storage temperature and aerobic exposure time on the fermentation characteristics, chemical composition, and mycotoxin levels of re-ensiled corn silage. Whole-plant corn harvested at the dough stage (39.77% DM) was initially stored at 20 °C, 30 °C, and 40 °C for 90 d and subsequently subjected to 0, 48, 72, and 96 h of aerobic exposure before re-ensiling, with three replicates per treatment. The results showed that corn silage initially stored at 20 °C and re-ensiled within 48 h of aerobic exposure exhibited the lowest pH (3.70), highest lactic acid concentration (56.78 g/kg DM), and highest Flieg score (99.67) among all temperature treatments (p > 0.05). In contrast, corn silage initially stored at 40 °C and re-ensiled after 96 h of aerobic exposure retained higher water-soluble carbohydrate (5.47% DM) and crude protein (7.32% DM) contents (p > 0.05). Aerobic exposure increased concentrations of beauvericin (71.89–864.92%), zearalenone (6.24–24.20%), and alternariol (0.77–1.89%) across all storage temperatures. Following 96 h of aerobic exposure, re-ensiling reduced these mycotoxin concentrations by 3.16–67.32%, 9.10–20.57%, and 0.62–6.79%, respectively. Overall, re-ensiling helped to preserve silage quality after aerobic exposure. The greatest benefits were observed when silage initially stored at 20 °C was re-ensiled within 48 h, while re-ensiling after prolonged exposure effectively mitigated mycotoxin risks.

In tropical and subtropical regions, stylo ( Stylosanthes guianensis ) is a main silage material, but there are some problems like poor fermentation quality and effluent production during ensiling due to its high‐moisture content after harvest. This study aimed to investigate the impact of incorporating dried soybean curd residue (SR) into high‐moisture stylo at different percentages (0%, 3%, 6%, or 9% of fresh grass weight) to silage production. The findings revealed that adding SR, even at a 3% rate, significantly enhanced the fermentation quality and aerobic stability, and reduced the protein degradation during ensiling, compared with the control ( p < 0.01). Effluent production resulted in the losses of dry matter and crude protein during the initial ensiling phase (3–15 days, p < 0.01), while no significant changes occurred during 30–60 days ( p > 0.05). Notably, the addition of SR at a 3% rate effectively eliminated effluent production (0.00‐ vs. 30.4‐mL·kg ⁻¹ FM). These results indicate that the inclusion of SR presents a promising and efficient strategy for producing high‐quality stylo silage without effluent.

BACKGROUND: Proteolysis during ensiling primarily occurs due to undesirable microbial and plant protease activities, which reduce the protein supply to ruminant livestock and cause a series of environmental problems. The objective of this study was to investigate the effects of the tannin‐tolerant lactic acid bacterium strain Lactiplantibacillus plantarum 4 (LABLP4) in combination with tannic acid (TA) on protein preservation in stylo (Stylosanthes guianensis) silage. The stylos were either ensiled without additives (control) or treated with LABLP4 (10⁶ colony‐forming units per gram of fresh matter), 1% (fresh matter basis) TA, 2% TA, LABLP4 + 1% TA and LABLP4 + 2% TA. Fermentation quality, protein composition, protease activity and bacterial diversity were determined at 3, 7, 14 and 31 days of ensiling.RESULTS: The combination of LABLP4 and TA decreased the pH, coliform bacteria count, non‐protein nitrogen, ammonia‐nitrogen (NH₃‐N) content and protease activities (P < 0.05) and increased the true protein content (P < 0.05) compared to the control. LABLP4 + TA led to a lower pH and NH₃‐N content than LABLP4 or TA alone (P < 0.05). On the last day (31 days) of ensiling, LABLP4 + TA increased the relative abundances of Firmicutes and Lactiplantibacillus (P < 0.05), except for the LABLP4 treatment, and decreased the relative abundance of Actinobacteria (P < 0.05).CONCLUSION: The combination of tannin‐tolerant LABLP4 and TA effectively improved the fermentation quality of stylo silage and reduced protein degradation by altering the bacterial community structure. © 2024 Society of Chemical Industry.

BACKGROUND: Purple Napier grass (PNG), a widely used grass rich in anthocyanin, is commonly employed in the production of silage. However, there is currently limited research on the retention of anthocyanin with or without additives during ensiling. Therefore, this study aimed to investigate the effect of different additives (Lactiplantibacillus plantarum CCZZ1 (LP), glucose, acetic acid, and dried soybean curd residue) on fermentation quality, anthocyanin content, and microbial community structure of PNG silage.RESULTS: Ensiling PNG without additives led to poor fermentation quality and rapid degradation of anthocyanin, resulting in a decline in antioxidant activity and the persistence of harmful microorganisms with high relative abundance. The use of additives, especially LP, effectively increased the relative abundance of L. plantarum, enhancing fermentation quality, the retention of anthocyanin (up to 166% increase rate) and antioxidant activity, while reducing the relative abundance of harmful microorganisms during ensiling for 30 days. Additionally, prolonged ensiling negatively affected the preservation of anthocyanin. Based on both fermentation quality and bioactivity, PNG should be ensiled for 30 days with LP inoculation.CONCLUSION: The employment of additives, especially LP, improved the fermentation quality, anthocyanin retention, and microbial community structure in PNG silage. To optimize both fermentation quality and bioactivity, it is recommended that PNG be ensiled for 30 days with LP inoculation. © 2024 Society of Chemical Industry.

Whole-crop wheat (Triticum aestivum, WCW) has a high nutritional value and digestibility. No-tillage (NT) can reduces energy and labor inputs in the agricultural production process, thus decreasing production costs. There are many studies on planting techniques of WCW at present, few being on no-tillage planting. This study aimed to compare the effects of different tillage methods and maturity stages on the yield, nutritive value, and silage fermentation quality of WCW. The experiment included two tillage methods (NT; conventional tillage, CT), two maturity stages (flowering stage; milk stage), and three years (2016-2017; 2017-2018; 2018-2019). Years had a strong influence on the yield and nutritional composition of WCW. This was mainly related to the amount of rainfall, as it affects the seedling emergence rate of wheat. Although tillage methods showed no significant effects on the yield, plant height, and stem number per plant of WCW (P > 0.05), compared to CT, the dry matter (DM) and crude protein (CP) yields of NT decreased by 0.74 t/ha and 0.13 t/ha. Tillage methods showed no significant effects on the nutritive composition of WCW (P > 0.05). The WCW at the milk stage had greater DM (5.25 t/ha) and CP (0.60 t/ha) yields than that at the flowering stage (3.19 t/ha and 0.39 t/ha) (P< 0.05). The acid detergent fiber concentration of WCW decreased by 34.5% from the flowering to the milk stage, whereas water-soluble carbohydrates concentration increased by 50.6%. The CP concentration at the milk stage was lower than that at the flowering stage (P< 0.05). The lactic acid concentration of NT (17.1 g/kg DM) silage was lower than that of CT (26.6 g/kg DM) silage (P< 0.05). The WCW silage at the milk stage had a lower NH₃-N concentration (125 g/kg TN) than that at the flowering stage (169 g/kg TN) (P< 0.05). Wheat sown by NT and CT was of similar yield and nutritional value, irrespective of harvest stages. WCW harvested at the milk stage had greater yield and better nutritional composition and silage fermentation quality than that at the flowering stage. Based upon the results of the membership function analysis, no-tillage sowing of wheat was feasible and harvesting at milk stage was recommended.

In terms of providing additional feeds and improving the soil fertility, planting forage crops during the fallow seasons is an effective strategy to promote resource utilization. The objective of this research was to compare the effects of planting different forage crops on the yields and nutritive compositions of forage and soil properties of winter fallow paddy in southern China. Five forage crops, including alfalfa (Medicago sativa, AF), common vetch (Vicia sativa, CV), milk vetch (Astragalus sinicus, MV), smooth vetch (Vicia villosa, SV) and Italian ryegrass (Lolium multiflorum, IR), were planted by monoculture on the winter fallow paddy in 2017-2018 (season 1) and 2018-2019 (season 2), respectively. The dry matter yield of IR was significantly higher than those of AF, CV, SV and MV (PPPP<0.05). The bacteria, actinomyces and fungi numbers on IR were the highest, while azotobacter number was the lowest. The catalase, acid-phosphatase and invertase activities of IR soil were the lowest. The numbers of bacteria, actinomyces and fungi of IR soil were the highest. IR and SV were the best crops to obtain forage and improve the soil. When producers pursue higher forage yield, we recommend planting Italian ryegrass. If the producers want to improve soil characteristics, smooth vetch is the most suitable plant. These results provide useful information to rice growers for cropping management when growing forage crops (based on the yield and nutritional value) or green manure (based on improving the soil fertility) as an alternative to late rice harvest.

The production of safe and high-quality silage has always been the main concern. This experiment aimed to investigate the impact of waste dried soybean curd residue (SR) and Lactobacillus plantarum CCZZ1 on the fermentation quality and microbial community of total mixed ration (TMR) silage based on Napier grass (Pennisetum purpureum). Napier grass was made into TMR, and SR at 3%, 6% or 9% on dry material basis was included, which replaced the equivalent amount of corn meal, then they were inoculated without or with Lactobacillus plantarum CCZZ1 (10⁵ cfu g⁻¹; LP). The research results showed that incorporating SR even at 3% resulted in significant reduction in ammonia nitrogen content (87.3 g kg⁻¹ total nitrogen vs. 109.7 g kg⁻¹ total nitrogen), increased lactic acid content (34.4 g kg⁻¹ DM vs. 25.5 g kg⁻¹ DM), and higher relative abundance of Lactobacillus (94.5% vs. 32.2%). Additionally, it led to decreased relative abundances of pathogenic microorganisms such as Escherichia coli (< 0.1% vs. 9.68%), Staphylococcus epidermidis (< 0.1% vs. 9.46%), and Streptococcus pneumoniae (< 0.1% vs. 8.53%) during the ensiling process. When SR was used together with LP inoculation, they were further improved. These findings suggest that the inclusion of SR, even at a 3% level without LP inoculation, can effectively improve the fermentation quality and microbial profile of TMR silage based on fresh Napier grass. This offers a promising technical approach to utilizing SR and producing safe and high-quality TMR silage based on fresh grass. Graphical Abstract