Maximize your acres with high corn silage diets

Posted on March 1, 2024 in Forage Foundations
By Jarrod Blackburn, Vita Plus dairy specialist

Land prices are soaring throughout the Midwest as the competition to purchase available acres increases.  Thus, dairy producers are looking for ways to maximize their acres from harvest to the bulk tank.

One strategy is to increase the amount of corn silage in dairy cow diets.  Previously, if roughly half of the forage dry matter (DM) came from corn silage, it was considered a “high corn silage diet.”  Today, some herds are effectively feeding diets in which corn silage accounts for 80% to 100% of the forage DM.

Yield and time management
Two major reasons for this change are the increasing yield potential and time management advantage of growing corn silage.  Depending on the year, alfalfa or grass fields struggle to produce more than 4 to 5 tons of DM per acre.  Harvest cost, time, weather and soil management are major hurdles to overcome when you’re running over the same fields three to five times per year to harvest haylage.  In contrast, corn tends to yield more than 8 tons of DM per acre and is only harvested once a year in the fall.

Consistency is a key advantage of corn silage compared with other crops.  Corn silage is chopped once annually and stored in large quantities.  This allows for more consistent diets with only minor changes depending on the season or other ingredient markets.  In contrast, haylage is harvested three to five times each year and it is more difficult to harvest this crop at the correct moisture.  Furthermore, it is stored in smaller piles and harder to pack to achieve optimal forage density.  Thus, the differences among the multiple cuttings and piles can potentially cause issues in balancing diets throughout the year.

Diet considerations
Improvements and selection of corn hybrids has made the transition to high corn silage diets more attractive.  Typically, corn silage will have higher fiber digestibility compared with alfalfa haylage.  Corn silage can contain upwards of 40% starch on a DM basis, so the need to feed ground corn decreases, leaving room to use lower-cost byproducts such as soy hulls, corn gluten feed, etc.  Often, these byproducts can bring in highly digestible fiber and help keep the rumen at a more stable pH while supplying cows with calories to produce at an elevated level.

Protein sources can be one of the largest expenses in diets.  Typically, producers have looked to alfalfa or grass haylages to supply protein to the rumen to decrease the amount spent on supplemental protein sources.  However, feeding higher corn silage allows us to rely on microbial protein to support milk production instead of feeding expensive rumen undegradable protein (RUP) sources (such as blood meal, heat-treated soy products, etc.).  Using more rumen degradable protein (RDP) sources (such as canola meal, soybean meal, etc.) allows the rumen to produce more microbial protein that is then absorbed in the lower gut and used by the cow.

Rations that include high amounts of trans-10 cis-12 conjugated linoleic acids (t-10 c-12 CLA) have a higher potential for milk fat depression.  CLAs are present in corn and soy byproducts, corn and corn silage.  Throughout the year, as corn silage ferments, starch digestibility increases, and more CLAs are available in the rumen.  A good nutritionist can manage the CLAs in the diet – and thus support milk fat production – by using feed additives, byproducts and/or other feed ingredients while still keeping the diet costs under control.

There are many different considerations when determining if a high corn silage diet is right for your operation.  The yield, consistency, and flexibility of corn silage makes high corn silage diets attractive to producers and nutritionists.

Depending on your farm, climate, and crop rotation, it may be worth having this discussion with your agronomist and nutritionist to determine if this is right for your operation.

My late father once told me, “They don’t make any more land, so we have to get every bit out of what we have each year.”

Category: Forage Foundations