Ruminant Nutrition Symposium: Novel microbial solutions to optimize production efficiency in beef and dairy systems

The livestock industry is in search of sustainable technologies that enhance profitability and sustainability of food animal production. Among these technologies, microbial solutions include living bacteria that may support soil, plant, and animal health. Bacterial inoculants have been the most used additives to modulate whole-plant corn silage fermentation, including homo- and heterofermentative bacteria. Bacterial inoculants can improve fermentation characteristics of grass silage, whereas the wide variation in chemical composition and management practices across cool- and warm-season grasses makes the outcome of inoculation less predictable. Tailored recommendations for bacterial inoculant species and strains, based on species and management practices are necessary to increase the predictability of silage inoculation, including whole-plant corn and grass silage. Microbial solutions are also used as feed additives for beef and dairy cattle, including Bacillus-based direct-fed microbials (DFM). Recent advancements in Bacillus-based DFM supplementation have shown promise for enhancing cow-calf productivity through improved gut health, immune function, and nutrient metabolism. Incorporating Bacillus-based DFM into stocker and feedlot receiving programs can improve feed intake and digestibility, health, and productivity of high-risk cattle. Bacillus-based DFM have also been used in feedlot diets to address public concerns with antimicrobial resistance, but also to improve cattle performance and reduce the incidence of diseases. Multispecies bacterial-based DFM are promising alternatives to counteract the potentially adverse effects of Salmonella, as these DFM supported the integrity of the intestinal epithelial cells under in vitro settings. In dairy cattle, most DFM-related research in mature cows has targeted improvements in rumen fermentation and enterocyte health. In general, improvements in milk production due to supplementation of bacteria-based DFM seem to be more consistent than those obtained with yeast-based DFM. Collectively, microbial solutions have the potential to optimize silage quality, enhance feed intake and digestibility by ruminants, support cattle health and performance, while fostering sustainable practices in beef and dairy production systems.