Silage Preparation, Processing and Efficient Utilization—2nd Edition

Silage preservation is one of the most efficient and widely adopted forage storage techniques, offering multiple superior advantages for modern ruminant feeding systems [1,2]. Compared with hay drying, ensiling effectively preserves forage nutrients under anaerobic conditions, minimizes losses of crude protein and water-soluble carbohydrates, and maintains high nutritional digestibility throughout long-term storage. This technology enables the year-round supply of high-quality forage, alleviating seasonal shortages of fresh feed and balancing livestock diet uniformity across different seasons [3,4]. In addition, proper ensiling inhibits the growth of spoilage bacteria, molds, and yeasts, reducing feed deterioration and improving feed safety. Furthermore, silage features favorable palatability and fermentation characteristics, which can promote rumen microbial activity, enhance feed intake, and ultimately improve livestock production performance [5]. Therefore, it is significant to explore novel technologies for silage production, processing, and high-value utilization. This Special Issue includes 10 original research papers themed on “Silage Preparation, Processing and Efficient Utilization—2nd Edition”. These studies demonstrate bright application prospects of silage, aiming to promote the development of the animal feed industry.

Sugarcane and corn make up 20% and 12% of global major crop output respectively. Both crops are widely cultivated in southern China, producing abundant residual sugarcane tops and corn stover annually. Moreover, epiphytic microorganisms regulate silage quality and aerobic stability, with epiphytic LAB exerting vital effects on early silage acidification. Yan et al. (Contributor 1) explored how epiphytic microbes of fresh forage impact silage quality and aerobic stability. They analyzed variations in chemical components, fermentation properties and microbial communities of sugarcane tops and corn stover across fresh, storage termination and aerobic exposure stages. Results revealed Weissella dominated the LAB population of the two forage materials and facilitated rapid initial acidification. Meanwhile, the acid-consuming fungal genus Candida mainly accounted for differences in aerobic deterioration between sugarcane top and corn stover silage.

As a typical agricultural residue, corn stover resource utilization is vital for balancing ecological and economic benefits. To boost its utilization efficiency, Zhou et al. (Contributor 2) incorporated Lentilactobacillus buchneri and varying doses of Artemisia argyi into corn stover, exploring additive effects on silage fermentation quality and aerobic stability. Results indicated that single supplementation of either substance effectively improved silage performance. Separate application of the strain and 30% Artemisia argyi elevated lactic acid level, reduced pH, suppressed harmful microbes, decreased ammonia nitrogen and mycotoxin contents, sustained high Lactobacillus abundance and strengthened aerobic stability. This optimized ensiling technique offers novel strategies for high-value reuse of corn stover, turning waste into high-quality feed and facilitating eco-friendly agricultural development.

With high yield and strong adaptability, corn (Zea mays L.) is globally cultivated and ranks among the world’s three staple crops, generating massive corn stover resources. China yields about 240 billion kilograms of corn stover every year. Efficient utilization of such agricultural by-products helps ease regional feed scarcity. Therefore, Du et al. (Contributor 3) comprehensively evaluated fermentation quality, bacterial composition, bacterial symbiosis networks, bacterial functions and pathogenic risks to explore regulatory mechanisms of corn stover silage fermentation. Results verified ensiling serves as an effective preservation approach. It drives bacterial community succession from Gram-negative to Gram-positive bacteria, forms LAB-dominated symbiotic networks, boosts starch and sucrose metabolism, and lowers pathogenic risks. Supplemental LAB and artemisinin further optimize fermentation performance and mitigate pathogenic hazards, qualifying them as ideal silage additives. The research offers practical references to relieve feed shortage via refined ensiling technology, with optimal dosages determined as 0.5% fresh matter of LAB (10⁵ CFU/g fresh matter) and 0.01% fresh matter of artemisinin (7350 U/g).

Proper field wilting after harvesting builds favorable conditions for silage fermentation. However, forage dehydration significantly affects plant soluble carbohydrate levels. Following harvesting, forage tissues continue intracellular metabolic consumption; inefficient dehydration aggravates the depletion of soluble carbohydrates, thereby reducing their final concentration. de Souza et al. (Contributor 4) assessed aerobic stability, fermentation characteristics, microbial diversity and nutritional composition of white oat haylage processed via three dehydration approaches: mechanical dehydration, mechanical treatment combined with bacterial compound additives, and glyphosate-based chemical desiccation. Overall, haylage that was treated with a mechanical–bacterial compound and chemical desiccation produced better fermentation results and enriched beneficial bacterial flora during fermentation.

Elephant grass (Pennisetum purpureum Schum.) is widely utilized in Brazil. It features high biomass yield, strong environmental adaptability, desirable nutritional value under proper cultivation and favorable palatability for dairy cattle. However, its high moisture, low water-soluble carbohydrate content and strong buffering capacity pose obstacles to high-quality silage production. Hence, dos Santos et al. (Contributor 5) explored the effects of varying bacterial inoculant dosages and 8% ground corn grain supplementation on fermentation traits, chemical constituents and in situ ruminal degradability of low dry matter BRS Capiaçu elephant grass silage. The results indicated that the addition of ground corn grain optimized silage fermentation performance, while bacterial inoculants exerted no notable improvement on silage quality under experimental conditions.

Lipid-enriched genetically modified forage benefits ruminant feeding and greenhouse gas reduction, whereas limited field access hinders standardized confined processing of transgenic biomass. Winichayakul et al. (Contributor 6) built a controlled system to cultivate, harvest and ensile high-metabolizable-energy perennial ryegrass and control materials. Results firstly confirmed that repeated confined cultivation, ensiling and long storage preserve the lipid advantages of high-energy ryegrass. The silage maintained elevated fatty acid levels, energy density and stable fermentation quality without nutritional deterioration, validating trait stability under enclosed management. This work bridges research transformation gaps, offering a regulated, scalable ensiling strategy for transgenic forage preservation, which can be applied to other confined genetically modified forage varieties.

The quality of whole-plant corn silage is modulated by multiple factors, including geographical longitude and latitude, harvest timing, and stubble height. Wang et al. (Contributor 7) quantified the main and interactive effects of ecological latitude, harvest timing, and stubble height on corn silage performance and explored whether latitude-specific optimization of harvest time and stubble height could improve the nutritional value, fermentation quality, and hygienic safety of whole-plant corn silage. Results indicated that latitude substantially shapes the optimal harvest schedule for whole-plant corn silage in Northeast China. Rising latitude delays and shortens the harvest window, particularly in areas above 45° latitude, to balance silage nutrition and hygienic safety. By contrast, low-latitude regions with adequate temperature and humidity support earlier and longer harvesting. A 40 cm stubble height is optimal for routine harvesting, while raising it to 60 cm preserves silage quality under delayed harvest conditions.

Biological inoculant efficacy varies with forage varieties and strain compositions. LAB-based additives are widely used to promote silage fermentation and aerobic stability, yet cross-species comparative studies remain limited. Jatkauskas et al. (Contributor 8) explored how eleven commercial inoculants with different homofermentative and heterofermentative LAB combinations affect fermentation progression, nutrient retention and aerobic stability of moderately wilted alfalfa, perennial ryegrass, and red clover-ryegrass mixed silage. They found compound commercial LAB inoculants substantially elevate fermentation quality, mitigate nutrient loss and strengthen aerobic stability of legume and grass silage in laboratory trials. For alfalfa silage, homofermentative LAB inoculants excel at boosting lactic acid accumulation, inhibiting proteolysis and reducing dry matter loss, serving as optimal additives for leguminous forages with strong buffering capacity. In perennial ryegrass silage, Lentilactobacillus buchneri-based treatments effectively enhance aerobic stability and restrain butyric acid fermentation. Inoculants blending homofermentative and heterofermentative strains deliver steady, comprehensive effects across diverse forages, suitable for raw materials with variable compositions or scenarios requiring balanced fermentation quality and aerobic stability. Conversely, groups without aerobic stability-improving strains exhibit inferior capacity to inhibit aerobic spoilage.

Cenchrus fungigraminus boasts high biomass yield, yet its high lignin and low soluble carbohydrate content confine its practical feeding utilization mainly to silage preservation. Existing studies on its silage application are constrained by undefined functional fermentation strains and unsatisfactory fiber degradation efficiency of conventional commercial inoculants, failing to satisfy practical production demands. Huang et al. (Contributor 9) assessed the fiber-degrading performance of three strains: indigenous Bacillus velezensis JC2 isolated from C. fungigraminus, commercial cellulolytic Bacillus velezensis (CBV) and Trichoderma longibrachiatum (CTL). Results indicated that screened Bacillus velezensis JC2 efficiently decomposed fibrous components, upgraded silage quality and nutritional value, showing promising prospects as a dedicated additive for this forage ensiling. The findings lay theoretical and technical foundations for developing exclusive silage inoculants tailored to C. fungigraminus.

Elephant grass (Pennisetum purpureum Schum.) is a high-yield tropical forage ideal for silage preparation. However, low dry matter content at optimal harvesting time tends to trigger fermentation defects and raise gaseous and leachate losses. Massena et al. (Contributor 10) investigated the effect of using wheat bran and cornmeal as additives on the fermentation characteristics and nutritional quality of elephant grass silage. Results showed that supplementing 12% (based on fresh weight) cornmeal and wheat bran elevated dry matter concentration and reduced gas and effluent losses. Additive treatment raised dry matter content to nearly 30%, stabilized pH around 4.2 and boosted dry matter recovery rate. Nutritional quality was markedly enhanced, with wheat bran contributing higher crude protein, ether extract and non-fibrous carbohydrate contents. Fiber content reduction also improved in vitro dry matter digestibility of silage.

This Special Issue presents 10 studies on silage preparation, processing and efficient utilization, covering epiphytic microbes, additives, harvest and dehydration processes, microbial communities, pathogenic risks, and novel silage materials. These findings reveal the regulatory mechanisms of silage fermentation, optimize technical parameters, and promote the high-value utilization of agricultural residues and diverse forage resources. Future research should focus on developing targeted additives, optimizing region-adapted silage technologies, and scaling up applications for genetically modified forages so as to upgrade the silage industry and support sustainable livestock farming.