Since October, Danish farmers have been required to feed their cows Bovaer—a methane-reducing additive intended to make agriculture more climate-neutral. However, several farmers have reported that some animals have become ill or died after consuming the supplement, Danish media, including Nyheder TV2, reports.
The new regulation, effective from January 1st, 2025, mandates that all farms with more than 50 conventional dairy cows feed Bovaer for at least 80 days a year. Many farmers began using the additive on October 1st. Reports describe cows suffering from fever, reduced milk output, or sudden death shortly after consumption. One farmer said he lost several cows, each representing a financial loss of about 10,000 Danish kroner (€1,300).
Bovaer, developed by the Dutch company DSM-Firmenich, contains 3-nitrooxypropanol (3-NOP), a compound that inhibits methane-producing enzymes in a cow’s digestive system.
Studies have shown that the additive can reduce methane emissions by up to 30% per animal. The European Food Safety Authority (EFSA) approved Bovaer for use in 2021, concluding that it was safe for dairy cows. However, EFSA also noted that no safety margin could be established for other animal species.
Some research has suggested possible negative effects on cows’ reproductive organs and feed intake at high doses. Aarhus University has announced that it will investigate the recent reports of illness and death among Danish dairy cows, stating that the findings must be taken seriously.
