FARM FACTS: Corn silage too dry?

Will Stallard, U.K. Extension Agent for Agriculture

I have had numerous reports of drier than normal corn silage this year. It is hard to answer all the questions about corn silage in one report. Nutrient analysis of corn silage, dry matter, nitrate levels, analysis of other feedstuffs, cow size, cow condition, environmental factors, and many more variables can impact the amount of corn silage you need to feed. I recommend you consult your nutritionist or county extension agent on your specific situation.
Here are a few things to consider when feeding corn silage:
Dry Matter (DM): Late season disease pressure and extreme drying conditions caused corn to dry down at a record pace this fall. Matter of fact, many corn silage bags will test pretty dry. Some may be 50% DM. This could pose some challenges to fermentation and increase spoilage on the face of the bag or pile. It can also open the door for molds. Thus, I strongly recommend sampling your corn silage and getting a nutrient analysis. If molds are present, the silage should be analyzed for that as well.
Protein/Energy makeup: Dry corn silage may be a bit lower in protein, but corn silage is mainly used for energy. In fact, corn silage can offer too much energy to gestating cows if intake is not limited. In most cases, it is least-cost to supplement some protein and limit-feed the silage to meet energy requirements. If your silage is dry, cows may consume much more dry matter than when the corn silage is 35% DM. This could compound problems with overfeeding energy via a corn silage based ration.
Ration palatability: If your corn silage is too dry, you may need to make adjustments to maintain a moist, palatable ration for finishing diets. Likely, cows won’t mind the extra dry ration… they will eat it. For most rations, the simplest solution could be adding water to the TMR. Another option is to utilize wet forms of co-product feeds like wet distillers grains, wet corn gluten feed, or brewers grains to add moisture and nutrients. If neither of these solutions are appealing, adding molasses is another option to improve palatability.
Feeding Strategy: Offering hay free-choice is standard practice. Using the same free-choice feeding strategy with corn silage can result in some pretty fat ladies. Palatability of corn silage is high. Cows will consume 90-100 lbs. of silage if given the opportunity. In nearly all scenarios, that is over-feeding. In my experience, dry silage leads to poor chop length, poor packing and lowered intakes due to poor fermentation.  Also, bunk management needs to ensure daily feeding and not putting out silage for 2-3 days as the spoilage in the bunk once exposed to oxygen will be much faster if the silage didn’t ferment properly.  One should always feed silage daily.
If your corn silage was harvested late, you will need to make ration adjustments to accommodate the additional DM in the corn silage. Fermentation may have been less successful. Poor fermentation of dry silage means it also won’t store as long once the pile, pit, or silo is open. A nutrient analysis is important and will ensure proper feeding levels can be attained.
For more information about feeding corn silage or livestock nutrition, contact Will Stallard, UK Extension Agent for Agriculture at the Lincoln County Cooperative Extension Service 606- 365-2447.