Effects of lasalocid, narasin, or virginiamycin supplementation on rumen parameters and performance of beef cattle fed forage-based diet.

Feed additives are nutritional tools that benefit dietary digestibility and nutrient utilization, alter ruminal fermentation routes, and improve cattle growth and efficiency, thus increasing productivity and profitability in beef cattle systems. Nonetheless, most of the current research focuses on supplementing feed additives in high-concentrate diets. Leaving a significant gap in understanding the influence of feed additives in cattle consuming forage-based diets, especially molecules capable of altering the fermentation process and, consequently, beef cattle performance. Therefore, this experiment aimed to evaluate the impacts of supplementing narasin (NAR), lasalocid (LAS), or virginiamycin (VRM) on rumen fermentation parameters, apparent nutrient digestibility, feed intake, and performance of Bos indicus Nellore cattle consuming a forage-based diet. Including commercially available feed additives into forage-based diets did not impact nutrient intake and digestibility of nutrients. The inclusion of NAR affected ruminal fermentation parameters toward propionate production, positively contributing to animal performance. Ruminal fermentation characteristics and animal growth were not impacted by dietary LAS and VRM, which could be attributed to the dose used in the current experiment, despite the manufacturer's recommendation. This research provides insights into NAR as an important feed additive for forage-based beef cattle diets.