When Green Policies Go Wrong: Cows Die After Climate Feed
3rd November 2025
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.