As conventional silage corn has increased in value in the dairy diet, so have brown midrib (BMR) hybrids, suggests Kathleen Emery, a dairy nutritionist with Mycogen Seeds/Dow AgroSciences.
“Dairy producers have increased their use of corn silage as a forage source over the past 10 years. It’s really been influenced by the high price of energy sources like corn. And, since BMR corn silage has more digestible nutrients, it can substitute for some corn.
“We have a lot of experience in the Midwest where people have substituted BMR for lesser digestible corn silages, and they’ve been able to increase the forage part of their rations upwards of 10% because so much of it is a higher-digestibility feed.”
BMR is a naturally occurring gene mutation that contains less lignin in its cornstalks than is found in conventional silage corn. “There’s 30% less lignin in BMR, so there are more digestible nutrients and cows eat more of it. In California, it’s been a real boon to producers because they’ve been able to eliminate between 3 and 5 lbs of purchased corn from the ration and increase the forage part upwards of 60% because of the higher fiber digestibility of BMR,” says Emery.
Mycogen’s BMR hybrids were the first introduced in the mid-1990s. Legacy Seeds also sells BMR hybrids. And, recently, DuPont Pioneer entered the market, says Bill Ramsey, Pioneer’s western livestock information manager.
“We introduced our first commercial BMR silage hybrid two years ago and added one more this year. We felt like we needed to get into the BMR arena to complement our full line of elite corn silage germplasms,” he adds.
BMR silage corns generally don’t yield as well as conventional hybrids, Ramsey says, and that makes some producers hesitate.
“For many of our growers in the West, we’re working with water-limited environments or production systems struggling to provide all of the forage that’s needed for the dairy enterprise. Those people in that position don’t want to sacrifice anything on the yield side.
“On the other hand, they realize that the BMR silage hybrids really have a good fit for those high-production cows so they still grow some and treat it as an ingredient. They’ll segregate it so they can feed it to those transition cows and the cows with the upper third in genetics.”