The use of antibiotics as growth promoters has been phased out due to concerns over microbial resistance, creating a demand for alternatives in pig feed. Benzoic acid (BA) has gained attention through its antimicrobial effects in the intestine, potentially improving nitrogen utilization, reducing diarrhea, and ultimately enhancing growth and carcass characteristics in pigs. Once ingested, BA moves to the liver, where it combines with glycine to form hippuric acid, which lowers urinary pH and reduces ammonia emissions. The aims of this study were to investigate the effects of increasing levels of BA on nitrogen utilization and metabolism affecting growth performance, ammonia emissions, and carcass characteristics, and to determine the optimal levels of BA for the growth and carcass characteristics when fed to pigs from weaning to market. The results showed that increasing levels of BA linearly improved nitrogen utilization, showed quadratic responses in body weight gain, feed efficiency, and loin eye area, and reduced urine pH and aerial ammonia emissions. Supplementation of BA within a range of 0.53% to 0.59% provided optimal improvement in body weight gain, feed efficiency, and loin eye area.

Read the full article in the Journal of Animal Science.