A management tactic to extend the grazing season is to plant corn with the purpose to graze the standing corn in the winter. This has to be planned in the winter of the previous year.
The biggest expense for graziers is the cost of stored feed at times when forage production is low. Pennsylvania graziers rely primarily on cool season perennial grasses to feed their animals, but these pastures typically show a decline in production in the dry and hot summer and they are dormant in the winter - typically from October to April. So you don't have a choice but to feed hay, haylage or grain in summer and winter. But the cost of stored forages is at least 2 times that of grazed forages per ton of dry matter so every day you are feeding stored feed you are incurring significant additional costs.
Stockpiling is a way of maximizing the grazing season by storing forages 'on the stem' in the field. One option that was discussed in a winter meeting is stockpiling corn. Corn has good standability in the winter and can provide adequate nutrition for winter feeding of certain ruminant animals. Key is the protein content for proper rumen function, and total digestible nutrients (TDN) for nutrition.
Dry cows or mature bulls need a minimum of 8% crude protein (CP) and 50% digestible nutrients. Growing heifers, yearling bulls and lactating beef cows need 10.5% CP and 57-65% TDN, while stockers need 12-14% CP and 70% TDN. Mature corn has a CP of 8.5%, TDN of 65.4% (NRC Nutrient Requirements of Dairy Cattle, 2001), and can therefore provide adequate nutrition for dry cows and mature bulls.
These numbers are book values and can vary of course due to many variables such as corn hybrid and management as well as animal breed and supplemental feed provided. If you consider planting corn for winter stockpiling, select a hybrid with high forage yield, high digestibility, low fiber content, and high fiber digestibility. Select a hybrid with strong stalks, hanging ears, adapted maturity group for your area, good disease and insect resistance, drought tolerance, and high dry matter yield. Provide all the other ingredients for a good corn crop, such as timely planting, proper fertilization, etc.
One area that will be different for grazed corn is weed control. Typically there is no need for post-emergence herbicides. When you select your herbicide program, make sure to respect grazing restrictions - see Table 2-2-18 in the 2017-18 Penn State Agronomy Guide. Interseeding a cover crop such as annual ryegrass/red clover mixture in corn that will be grazed in the winter is a great option - the cover crop can provide a high-quality fodder to add to the corn that makes for a great grazing cocktail. The cover crop roots provide a 'geotextile' under the soil helping to make the soil more resistant to compaction. Soil compaction is perhaps the biggest threat to winter grazing when soil is not frozen. It is therefore recommendable to select well-drained fields where you plan to graze corn this late.
Still, it is important to keep cattle out of the field when the soil is too wet. Strip grazing is recommended for grazing stock-piled corn. This means you use movable electric fence to give animals only enough for a short period of time (no more than three days at a time). This is important to avoid the cattle picking and choosing and running down a lot of corn which they will not eat once it is soiled. Backfencing will help keep soil compaction to a minimum. OSU Fact sheet ANR-11 is a great resource to learn more about grazing corn.