Starting With The End In Mind

Mycogen Seeds has become an industry leader in breeding silage-specific corn hybrids by starting with the end in mind, writes Sarah Mikesell, senior editor
calendar icon 22 March 2011
clock icon 5 minute read

When it comes to corn silage, Dennis Craig, product development agronomist with Mycogen Seeds, says you have to develop hybrids with the end consumer as your focus - in this situation, that consumer is a dairy cow. Because corn grain hybrids are developed for a different purpose, you have to throw much of that knowledge out the window when considering the key breeding characteristics of silage corn hybrids.

"In a silage hybrid, you want the nutritional components that are important to the dairy cow to efficiently produce milk," Mr Craig said in an interview at World Ag Expo in Tulare, California. "Of importance are good neutral detergent fibre (NDF) digestibility with starch and good stay-green qualities - we need hybrids with good plant health that will stay green up to the time that it's chopped and harvested for silage."

Since Mycogen supplies silage hybrids across the US, they need shorter maturity hybrids for the Midwest, and up along the Canadian border, they're breeding 75- to 85-day relative maturity hybrids. But for California, their goal is to breed 130-day relative maturity hybrids.

Mycogen has been testing their western US hybrids for four years in an effort to push the length of relative maturity BMR hybrids for the marketplace. Brown midrib (BMR) is a non-GMO corn hybrid that includes a naturally occurring mutant gene that causes the corn plant to create less lignin in the cornstalk. Less lignin means higher fiber digestibility, which leads to greater dry matter intake (DMI) and increased milk production.

US-wide, Mycogen plants thousands of silage research test plots per year as they work to find the germplasm that works best for each type of climate.

"Corn is a very fickle plant; one hybrid might work very well in a town, and then 100 miles away it won't because of the environmental conditions," Mr Craig said. "So, the genome-by-environment interaction is the very reason that we have to do a lot of testing."

Because Mycogen Seeds is owned by Dow AgroSciences, a global company, it's allowed them to pull in germplasm from other parts of the world to reach their breeding goals.

"The germplasm from South America has a good fit for the western United States because it's more of a tropical-type germplasm," he said. "The US has concentrated on breeding programs with a #2 yellow dent corn. When we bring in tropical germplasm and cross it with the temperate North American germplasm, we're coming up with some very unique hybrids that have very high tonnage capabilities for dairymen, but we also needed to think about the nutritional qualities."

Mr Craig said that's where BMR really proves itself because it is much more digestible for the cow because the plant has less lignin. Generally, conventional corn hybrids will have NDF digestibility percentages in the low to mid 50s, but BMR hybrids are generally 68 per cent and higher for NDF digestibility.

"That's where the dairyman picks up milk production," he said. "Sixteen different universities have proven that they'll gain, on average, 4.8 pounds more milk, per day, per cow."

With the current high cost of corn grain, it gives dairymen the option to pull a portion of their corn grain out of the ration and increase the amount of forage. Craig says they've also seen a positive effect with health in the animals.

"As you know, a dairy cow is designed to digest forages, she's got the big rumen, like a 55-gallon drum inside of her," Mr Craig explained. "It's the microbes and the microflora inside the rumen that break down that forage and fiber components."

Mr Craig said BMR corn silage makes economic sense with increased milk production and being able to cheapen up the ration by pulling some corn grain out.

"If you can pull three to five pounds out (with corn futures) at $7 a bushel, that's pretty good cost savings to the dairymen," Mr Craig commented.

BMR Ration Formulation Tips

Mycogen recommends the following tips to dairymen who are adding BMR to their ration formulation:

  1. Plan ahead. Before growing BMR corn, meet with your nutritionist to discuss feeding strategies.
  2. Feed BMR for the highest return on investment.If you plan to feed BMR to only a portion of your herd, high-producing groups will generally show greatest response.
  3. Evaluate storage needs. Although BMR can be mixed with conventional silage in a ration, it is best to store the different types of silage in separate structures.
  4. Work with your nutritionist on ration formulation. Ask your herd nutritionist to create a sample diet with BMR corn silage and other ingredients on the farm to predict the impact it will have in dry matter intake, rumen efficiency, grain savings and milk production.
  5. Test silage after harvest. Select a lab that has experience analyzing BMR corn silage using both near infrared spectroscopy (NIR) and wet chemistry/in-vitro methods.
  6. Adjust for higher silage digestibility. When formulating rations with BMR, use dynamic ration formulation software. This software will help optimize health, productivity and profitability. Higher levels of digestible fiber will enhance rumen microbial efficiency and replace a portion of the energy from starch sources. This leads to higher dry matter intake (DMI). Feed at least 15 pounds of dry matter BMR corn silage per cow per day. This provides a solid base of digestible fiber.
  7. Monitor herd performance. The fiber in BMR corn silage is more digestible and may result in an increase in group DMI. Keep an eye on total ration starch, NDF and effective fiber levels. Additional sources of effective fiber may be needed to maintain optimal rumen function and control rate of passage through the rumen. If you see changes in manure consistency, milk components and milk urea nitrogen (MUN), work with your nutritionist to fine-tune the diet.
March 2011
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