Molasses-based liquid feed for energy-nitrogen synchronization and its performance potential in ruminants under tropical regions: a review.

Livestock productivity in tropical regions is constrained by low-quality roughages that limit intake, digestibility, and animal performance. Liquid feed supplementation, particularly molasses-based formulations combined with urea, has emerged as an effective strategy to overcome these limitations. Molasses provides readily fermentable carbohydrates that stimulate rumen microbial activity, enhance the fermentation of fibrous feeds, and increase dry-matter intake. Urea contributes a nitrogen source for microbial protein synthesis, thereby improving crude-protein digestibility and nutrient utilization. Numerous studies have reported that liquid feed supplementation can enhance rumen fermentation efficiency, increase volatile fatty acid (VFA) production, and may support the activity of cellulolytic bacteria responsible for fiber degradation. Although the rapid hydrolysis of urea may lead to elevated ruminal ammonia concentrations, this risk can be effectively managed through appropriate formulation and feeding practices. Liquid feed supplementation has also been shown to improve growth performance and, in some cases, milk yield and composition. Further research is needed to optimize the balance between nitrogen and energy release, establish species-specific supplementation rates, and evaluate long-term effects on animal health and sustainability. Overall, liquid feed supplementation represents a practical feeding strategy with potential economic advantages for improving feed utilization and productivity in tropical ruminant systems.