In 2019, the Scottish Government set ambitious targets to deliver net-zero greenhouse gas (GHG) emissions by 2045. In 2018, agriculture was responsible for 18% of Scotland’s total GHG emissions. More than half of this was attributed to methane (56%) with most methane arising from enteric fermentation (produced during digestion of feed by cattle and sheep). The Government’s net-zero target, therefore, creates strong demand for methane-mitigation technologies. This report provides a rapid evidence assessment of two feed additives – Bovaer and Agolin Ruminant – which are being developed to reduce enteric methane emissions.