Features Agronomy Seeding/Planting
Brown mid-rib corn hybrids gain expanded foothold in Canada

At first glance, BMR corn resembles other hybrids, yet the taller plants mean higher tonnage.

Lower lignin provides boosted milk production and other benefits

Brown mid-rib corn hybrids (BMRs) developed by Mycogen Seeds Canada are steadily gaining a foothold in Canada because of the boosted milk production they provide.

Jarek Nowak, Mycogen Seeds Canada Business Manager, says “Higher milk production is the most often stated benefit of using BMR in a dairy ration.” More than 300 dairy producers, mostly cattle but also some with goats, in Ontario and Quebec planted BMR hybrids in 2008.

Nowak says “Multiple return over feed cost (ROF) studies conducted in Canada by an independent consultant since 2005 over the last three years have demonstrated that on average, our producers realized a gain of around $1 per day per cow. We anticipate that the current grain pricing will result in even higher returns.”

These studies align closely with North American research conducted since 1999, says Nowak. “Sixteen university and independent reports indicate cows fed BMR corn hybrids produced an average of 2.1 litres more milk per cow per day than cows fed non-BMR hybrids.”

Increased fibre digestibility provides other benefits as well. Nowak says, “These broader benefits are directly related to increased forage content in the ration, making it a “healthier” diet for a ruminant animal. A higher forage diet leads to fewer problems with the digestive system and associated symptoms (e.g., acidosis, hoof issues), a better conditioned animal with improved conception rates and extended productive life cycle of an animal. In addition, reduced manure production has been observed.”

Challenges to use
Brown mid-rib hybrids were first discovered in the 1920s. Dr. Bill Weiss, a crop scientist at Ohio State University says in the late 1990s, companies began looking at it again. “Dairy cows tend to eat more because it’s more digestible and doesn’t fill them up as much,” says Weiss. However, Weiss says the digestibility benefits come with higher seed costs and lower yields. 

Karl Nestor, a scientist with Mycogen Seeds, says, “Our plant breeders have been working to eliminate yield drag and they’ve been very successful at it.” Yield is currently about four to five percent lower than other common corn hybrids. “I suspect that in the near future,” says Nestor, “it will be history. Even with the yield drag, it’s still more profitable for dairy farmers.”

Nowak adds, “The two year average yield for the leading BMR hybrid is around 18 tonnes per acre, based on 45 Canadian production sites. In high yield environments, it delivered average yields of around 22 tonnes per acre.” 

Preparing for BMR success
“We emphasize three points when recommending BMR hybrids,” says Nowak. “First, plant it on your best land. BMR silage is the highest value forage crop you will be producing on your farm, so try to produce the most you can. Second, test for moisture before you harvest as brownish plant pigmentation associated with the brown mid-rib gene makes them look more mature than they are.”

Finally, Nowak recommends harvesting BMR at an average chop length of 3/4”- 1” to ensure that effective fibre functionality is maintained. A longer chop length also helps prevent “over packing” or crushing and reduces seepage. Nowak adds “BMR hybrids from production and ensiling perspective are the same as other silage hybrids.”

Field issues aside, Nowak says the main challenges with BMR adoption have been found in the improper incorporation of BMR silage in the dairy ration. “First, we found inconsistencies in near infrared (NIR) tests for neutral detergent fibre (NDF) digestibility, as BMR silage tests differently than a regular corn silage and requires its own calibration,” he says. This meant some nutritionists were using incorrect results to calculate and balance dairy rations. “In response to that challenge,” says Nowak, “we introduced a free-of-charge testing program utilizing in-vitro wet chemistry tests.

A second challenge has stemmed from the fact that not all nutritionists were recognizing BMR as different from a regular corn silage. In order to correct this and improve the understanding of how to properly incorporate BMR silage as a feed component in dairy rations, Mycogen introduced a series of seminars in Ontario and Quebec led by Nestor over the last two years. “These presentations were directed at maximizing producers’ experiences with BMR,” says Nowak. “I believe that most nutritional companies are ready to assist BMR producers in taking a full advantage of this technology.”

In addition to nutritional benefits with BMR hybrids, some research indicates reduced manure production from cows.

Current and future use
Currently, Mycogen Seeds offers BMR hybrids in Ontario and Quebec. “Sales quadrupled from 2006 to 2008 plantings,” notes Nowak. Mycogen’s BMR selections have improved since 2006 when the company sold only two hybrids, neither of which had any herbicide or insect traits. “This has changed significantly with the 2009 product lineup including five BMR hybrids,” says Nowak.

Further enhancements, to include herbicide and insect traits, have been added, along with early maturing hybrids.

In looking even farther down the road, Nowak says “the mid-term objective is to increase the number of hybrids in earlier maturing zones and continue on expanding herbicide and insect trait choices. The breeding effort has been directed at maintaining digestibility and improving field performance consistency under stress conditions.”