Non-lactating and non-dairy cattle are the largest animal source of methane emission, contributing to global warming. The use of feed additives has been demonstrated to be an effective strategy to reduce enteric methane emission from ruminants. This study aimed to investigate the effect of supplementing growing calves from 5 mo of age with the methane inhibitor 3-nitrooxypropanol (3-NOP). A total of 60 calves were assigned to 1 of 2 treatments: control (no 3-NOP) and 3-NOP (121 mg/kg dry matter). The calves received their diets for 12 wk. Supplementing 3-NOP decreased methane production (g/d) by 29.8%, methane yield (g/kg dry matter intake) by 19.4%, and methane intensity (g/kg body weight) by 27.9%, but calves that received 3-NOP had a lower feed intake and body weight gain. It can be concluded that 3-NOP is a promising strategy to decrease methane emission of growing calves, although it is essential to closely monitor its variable performance implications.

Read the full article in the Journal of Animal Science.