There is a question on the “Consultant Side” of CWT about cutting corn silage at a high level. Does anyone have research or data on this issue?
If you want to send it to info@theCWTgroup.com I can post your data on the Consultant side. Any direct reply here will be seen by all the consultants plus all the general industry registrants.
This was a hot topic 15 years or so ago. I think there was research at a few universities. I found a Hoards Dairyman article ( https://hoards.com/article-2942-Corn-silage-High-chop-or-traditional-cut.html ) by Ev Thomas and Bill Mahanna that lists a couple.
The main points are as expected: cut higher (by 6-12″), lose some yield, gain a little starch and NDF digestibility, lose a little NDF.
A point I didn’t remember was that hybrids varied in their response to this management tool. I guess I shouldn’t have been surprised…
As I remember discussions in the field, the gain in quality did not make up for the loss in yield and increase in cost/acre. However, the viewpoint at the time was to improve quality and there were more cost effective ways to do this.
This growing season, viewpoints may shift with high silage yields in many areas. If your customers are looking at more silage than they can store and don’t have a good market to sell excess, it might make some sense.
Penn State Dairy Extension has an excellent article on this topic. In Google or other search engines, type “corn silage cutting height” and the article should come up. Here are the high points from the article that summarized a number of trials.
1. Cutting corn silage higher reduced yield per acre but improved ADF, NDF and CP digestibility.
2. Feeding the high cut corn silage allowed you to feed more corn silage in the diet.
3. Feeding the high cut corn silage reduced milk fat % with no effect on milk protein %.
4. Drop in milk fat when feeding high cut corn silage was significant, 0.3 units. Milk yield was increased by 3 pounds per cow.
If you have really tall corn silage (consider yourself fortunate), not the case in parts of WNY and Michigan, to make this strategy work, you have to prevent the drop in milk fat percent because the increase in milk does not make up for the loss in butterfat. A herd milking 87 pounds with a 3.8% fat test, will ship 3.3 pounds of milk fat/cow. If feeding high cut corn silage increases milk to 90 pounds but decreases milk fat to 3.5%, you will ship 3.15 pounds of milk fat/cow. Not a winning proposition since feeding high cut corn silage only reduced ration cost by 9 cents a cow/day. My advice is to chop the tall corn silage at regular height but treat it with a silage inoculant that boosts NDF digestibility. A second alternative is to feed a live yeast to boost rumen pH and increase fiber digesting bacteria. If you chose to chop high,, make sure you measure NDFD, and UNDF and balance the diet accordingly.