Editor’s note: In last month’s Practice Builder column, dairy nutritionist Steve Woodford, of Sheboygan Falls, Wis., discussed how he works with agronomists to improve feed quality at his clients’ farms. The following article in the October issue of Dairy Herd Management is a logical follow-up to Woodford’s column.
Getting a good crop of corn silage is no small feat, considering the synchrony of events involved.
Look at the agronomic aspects, including hybrid selection, planting date, plant density, row spacing, soil fertility, pest management, plant maturity and the weather, among others.
It used to be that a careful farmer could orchestrate these, but more and more farms are now hiring custom harvesters, which adds another element — and more uncertainty — to the equation. When the custom harvesters show up, they don’t want to wait around; they want to take the crop, regardless of the moisture content.
Too much can go wrong. That is why it is important to get your nutritionist and crop consultant together in one place to plan for next year.
It’s the crop consultant’s job to try to get the best yield and the best quality out of the ground. The nutritionist, meanwhile, takes what is grown and tries to make it work in a ration. But wouldn’t it be better if they coordinated all of this ahead of time? Everyone’s objective should be to feed the cows.
“That ground is not there to make silage; that ground is there to make milk,” says Jerry Weigel, manager of nutrition and technical service for BASF Plant Science.
There are a number of places where nutritionists and agronomists can do a better job coordinating their efforts.
For instance, many farms aren’t harvesting their corn silage at the proper moisture level. Forage crop consultant Ev Thomas, who spent many years at the Miner Research Institute in New York as vice president of agricultural programs, says he sees it all of the time: Too many farms are harvesting corn silage that is barely at 30 percent dry matter or even in the high 20s.
Instead, the crop should be harvested at a minimum of 32 to 33 percent dry matter if it is to be ensiled in a bunker silo, says Thomas, who now serves as a consultant with Oak Point Agronomics in Hammond, N.Y.
There is a significant quality difference between corn silage harvested at 30 percent dry matter versus 35 percent, he points out. The edge definitely goes to the 35 percent corn silage. The amount of grain on the plant increases very rapidly as it goes from 30 percent dry matter to 35 percent, he adds.
It is what Thomas refers to as “maturity management” — and definitely an area where the nutritionist and crop consultant can do a better job of coordinating their efforts.
For instance, the nutritionist is the one who looks at the feed analysis. He is keenly aware of the quality differences that can arise when corn silage is harvested at lower-than-optimal dry matter levels. Perhaps he can work with the crop consultant in the following manner:
Emphasize the importance, from a quality standpoint, of harvesting at the right maturity. Often, this can be equated to “milk per acre of corn silage harvested.” And, it’s also good to discuss net energy for lactation (NEL). If the corn silage is harvested early and has a low NEL of 0.65 Mcal/lb (versus 0.76 or higher), the farm may have to buy extra grain to make up for the energy deficiency.
Along with the crop consultant, advise the farmer to choose hybrids that have the right maturity characteristics for the farm’s management.
Once the corn is planted and making good progress, pay attention to when it reaches the silking stage. Roughly 42 to 47 days after silking, corn silage will be ready for harvest, according to Joe Lauer, extension agronomist at the University of Wisconsin. But don’t base it solely on that; the crop still needs to be tested for dry-down, he adds. It’s just a rule-of-thumb that 42 to 47 days past silking is when the corn kernels reach the half-milk line, and that is roughly the time to start chopping. At the very least, it can give the farm an estimate of when the custom harvesters need to show up. Further updates can be provided as dry-down progresses.
If the corn is still too wet when the custom harvesters show up, you can raise the cutter bar on the chopper and maybe gain two to three percentage points on dry matter, Lauer says. That’s because the upper part of the plant is typically the driest.
Maybe the problem is at the other end of the maturity spectrum — people waiting too long to harvest. Steve Woodford, a dairy nutritionist in Sheboygan Falls, Wis., often hears producers say “no, I have not cut alfalfa yet as I don’t see buds” or “no, I have not chopped corn silage yet, it looks too green.” Ultimately, many producers wait too long. So, Woodford will remind them the following spring what consequences that had on feed quality.
It’s more than just maturity, points out Mark Schultz, sales agronomist for BASF Plant Science. Getting a good crop also involves choosing hybrids with the right input traits, such as herbicide resistance and pest resistance. These can influence crop yield and quality.
Schultz says he saw a surprising amount of corn borer damage while on a silage tour in Pennsylvania and New York this past August. That damage could have been avoided by choosing hybrids with resistance to corn borers. Meanwhile, quality has been compromised and the nutritionist will have to deal with that.
In that case, the nutritionist may want to have a say in next year’s hybrid selection.
Make sure his voice is heard.
Again, members of the management team shouldn’t just be seeing plants in their minds; they should be seeing the amount of milk that can be produced from those plants.