Features Agronomy Other Crops
More milk in the tank, more dollars in the pocket

Although brown mid-rib corn has been around since the 1920s, it has only been
within the last dozen years that dairy producers have been able to take advantage
of its nutritional benefits.

BMR corn, named after the brown mid-rib gene, has lower lignin content than
other hybrids so it produces more digestible silage. Lignin is the cement between
the plant's cell walls that makes the plant stay upright. Animals have no way
of breaking down the lignin so the fibre passes right through them, increasing
waste. However, if the fibre is more digestible, less grain needs to be fed
and milk production increases.

Since the introduction of Mycogen's Silage Specific BMR hybrids in 2005, more
dairy producers are seeing the benefit of making the BMR corn silage part of
their nutritional programs. "Brown mid-rib hybrids have up to 40 percent
less lignin than conventional corn, so the plant's fibre is up to 30 percent
more digestible," explains Dr. Doug Yungblut, nutritionist with Mycogen
Seeds.

"By feeding less grain, producers reduce the risk of acidosis and improve
the health and longevity of their cows. Producers tell us cows that maintain
their weight at the beginning of lactation are healthier and get back in calf
sooner."

Increased forage, increased production
So just how much can BMR corn silage improve milk production? To find out, Mycogen
Seeds conducted a detailed study of three Canadian dairy herds with varying
herd sizes and management conditions.

Gillette Farms, the largest of the three farms that participated in the study,
milks more than 400 cows and started feeding them BMR in October 2005. The other
two farms each milk less than 100 cows. One farm has been feeding BMR corn since
October 2004 and the other since November 2005.

Gillette Farms manages two herds near Embrun, Ontario: one high producing show
herd and a more commercial production herd. Since starting to feed BMR silage
to the whole herd, they have seen an increase in the 305 day projection for
the show herd of 628 kilograms while the commercial herd increased by 941 kilograms.
Corn silage feeding levels have increased from 8.1 to 9.5 kilograms per day
on a dry matter basis with 63 percent forage in the ration.

Feeding BMR silage has another benefit: reducing manure input while increasing
milk production. A 2006 Ohio State study found that feeding BMR silage reduced
manure to 69.9kg/day compared to 72.9kg/day when feeding a dual purpose corn
hybrid.

"We gain the most production at the beginning of their lactation,"
says Marc Patenaude of Gillette Farms. "By having the cows on BMR, they
eat more of their ration and any increase in dry matter intake helps their production."

Patenaude, who is planting 200 acres of BMR corn this year, says that feeding
BMR corn helps reduce the amount of grain being fed and improves milk production.

"We were feeding 10 kilograms of high moisture corn per day, but now that
we're feeding BMR, we can bring that down to six kilograms per cow per day.
We find that when we are feeding BMR, the health of the cow is better, she is
eating more of her ration and she is more productive."

More milk per acre
Of concern to some producers is that BMR hybrids yield lower than top performing
silage corn hybrids, but Patenaude points out that production gains more than
compensate for lower yields.

"While it's not the highest yielding corn in the field, in terms of milk
per acre, it's the best," says Patenaude. "It's so much higher in
digestibility that the cow will produce more milk on the same acreage."

According to Yungblut, the difference between genetics, management conditions
and feed quality will result in varying outcomes at each farm where BMR silage
is fed.

"In some cases, we see a rapid increase in milk production, as at Gillette
Farms, while others, like Farm 3 in the study, will show a more gradual rise,"
says Yungblut. "And in other herds, like Farm 2, there may not be a change
in production but the cows will be fed a healthier, higher forage ration at
a lower cost and still produce the same amount of milk. On average, dairy producers
who feed BMR silage should experience increased production levels with healthier,
higher forage rations." -30-

The care and feeding of corn silage
Select silage hybrids on the basis of maturity, disease and insect resistance
requirements for the specific growing region. Plant the hybrids in highly fertile
soil that receives abundant rainfall. If possible, BMR hybrids should be planted
first.

Harvesting silage at the appropriate moisture content is one of the keys to
a successful silage crop. If harvested too wet, silage loses soluble nitrogen
and carbohydrates to seepage. Silage that is chopped too dry may lose leaves,
will not pack well and sets the stage for inefficient fermentation. Depending
on the type of silage storage, the optimum whole plant moisture is between 63
to 70 percent.

"Make sure the moisture is correct," advises Dr. Doug Yungblut, nutritionist
with Mycogen Seeds. "Appearances can be deceiving so it is critical that
it is tested. BMR silage should be harvested at two percentage points drier
than normal and whether it's processed or not, it should be chopped longer.

"Wait at least two weeks before you analyze the samples because freshly
made silage is not reflective of what cattle will eat. If you can, wait the
two months and then have it analyzed, or re-analyzed."

Whatever corn silage is being fed, it is vital that producers work directly
with their herd nutritionists to ensure the cattle are being fed a well balanced
ration. For BMR corn, it is especially important.

"Be sure to have an NDF digestibility analysis on the BMR sample so your
nutritionist can determine how much dry matter intake increase is likely to
occur and the ration can be adjusted accordingly," says Yungblut.