UK Arla trial of Bovaer on 30 farms ends with results under review. Bovaer suppresses cow stomach enzymes to slash methane emissions 30-45%. UK regulators approve Bovaer and declare treated milk safe. Danish farmers report cow fever, diarrhoea, and deaths after Bovaer use. Denmark mandates methane suppressants like Bovaer on 1400 of 2000 dairy farms. Danish authorities collect data on sick herds but note unclear affected numbers. Aarhus University studies found no such disease patterns from Bovaer. Manufacturer DSM-Firmenich insists Bovaer safe, used by thousands in 25 countries for 3 years. Company states Bovaer not factor in prior health cases. NFU demands animal welfare priority for methane additives.