Red clover doesn’t yield quite as well as alfalfa, and it dries more slowly for hay. But red clover silage may be superior to alfalfa silage as a dairy feed, and can help reduce manure nitrogen levels.

That’s according to Glen Broderick, a USDA-ARS scientist in Madison, WI. Broderick says red clover has an enzyme called polyphenol oxidase that reduces protein breakdown in the silo. Typically, more than half the protein in alfalfa silage breaks down into non-protein nitrogen (NPN), which is used inefficiently by cows. On average, red clover silage has 40% less NPN than alfalfa. If not used by animals, NPN is excreted.

In two recent feeding trials, cows produced roughly the same amount of milk on less feed when fed silage made from red clover instead of alfalfa. On average, they produced 68 lbs of milk a day on 54 lbs of alfalfa dry matter vs. 69 lbs of milk on 49 lbs of red clover dry matter. That’s a 10% improvement in feed efficiency and a 10% greater energy value for cows fed red clover, says Broderick.

In the two trials, protein efficiency was 17% better on red clover than on alfalfa. Even if this improvement applied only to the first half of the lactation, when cows are fed the most protein, nitrogen excretion would be reduced by about 1.5 tons per year on a 100-cow dairy farm, says Broderick.