Yield and quality are important for any crop you grow, but when it comes to silage corn, you may need to expand those definitions a bit. That’s because the whole corn plant – leaves, stalk and grain – winds up in the feed bunker, unlike feed wheat or barley, which contribute only grain to a cattle ration. So the management decisions you make, from hybrid selection to harvest date, can make a big difference as to how each component of your corn plants contribute to the overall nutritional value of the resulting silage.
Here are some tips to think about.
Understand starch and fibre sources. Silage corn has two nutrition pools – green and yellow. The green pool, that’s the leaves, stalks and husks, are where the digestible fibre comes from. The yellow pool, the grain, is where the starch comes from and is all energy. It means you want to pay attention to the whole plant as it grows and matures so that you capture the best of both pools in your silage.
Don’t get too aggressive with hybrid selection. Getting your corn plants to physiological maturity is key to achieving maximum nutritional value from the crop. In fact, plant maturity can affect nutrition more than hybrid type and plant breeding. So choose a hybrid with relative maturity (RM) and corn heat unit (CHU) ratings suited to your area and resist the urge to choose one that may have a nutrition profile you like but has an RM too long for your region.
Understand plant physiology. Quality silage is all about the digestibility of both starch and fibre. In the yellow pool, cobs need to be at a half milk line to achieve both good starch content in the overall forage, and good digestibility. If the hybrid you’re growing can’t get to that stage of maturity before harvest then nutritional quality will suffer.
Over in the green pool, specific hybrid types such as BMR and TMF, have been bred for low lignin content or leafier growth habit, both of which contribute to fibre digestibility. But keeping an eye on maturity is still critical, even with these purpose-built hybrids.
Lignin, for example, forms to support corn stalks as they grow. So regardless of hybrid, the taller your plants get, the more lignin they produce. There is an argument to be made that paying attention to crop maturity has a bigger impact on the digestibility of whole plant corn silage than hybrid type.
The bottom line is that the right hybrid with the right maturity and yield that’s harvested at the right time will usually result in silage of high nutritional quality. Talk to your CAM if you want help timing your harvest.
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