In Ireland a practical test by Teagasc shows that the product 3-NOP (Bovaer) can reduce methane emissions from dairy cows by a quarter during the winter barn period. The cows were given a ration of grass silage, corn silage and concentrates, with the only difference being 3-NOP added or not. The cows with the addition produced the same or slightly more milk, fat and protein. Methane emissions were reduced by 26 percent per cow per day and 27 percent per amount of fat and protein produced. However, in Ireland cows are on pasture for a large part of the year, usually day and night, while 3-NOP only stays in the rumen for three hours. To be effective, the product should therefore be fed and consumed throughout the day.