This study evaluated the efficacy of 3-nitrooxypropanol (3-NOP), a feed additive marketed as Bovaer®10, on enteric methane (CH₄) emissions in Hanwoo steers. Twelve Hanwoo steers (average body weight 342 ± 17 kg) were assigned to one of three dietary treatments: a control diet or the same diet supplemented with either 100 mg or 150 mg of 3-NOP per kg of dietary dry matter. Methane emissions were measured using whole-body respiratory chambers. The results showed that supplementation with 3-NOP reduced absolute methane emissions by 21.9% and 29.5%, and methane yield per unit of feed intake by 22.9% and 27.7%, for the lower and higher doses, respectively. Energy losses as methane (Y_m) were also significantly reduced by 22.8% and 27.6% for the lower and higher doses, respectively. While there was a slight reduction in feed intake at the higher dose, no adverse effects were observed on body weight, weight gain, or feed efficiency. Additionally, shifts in rumen fermentation patterns were noted, including an increase in ruminal pH and changes in volatile fatty acid profiles, indicative of altered hydrogen utilization. In conclusion, dietary supplementation with 3-NOP effectively reduced methane emissions in Hanwoo steers without compromising animal performance, highlighting its potential as a practical mitigation strategy in beef production systems.

Read the full article in the Journal of Animal Science.