Corn harvest is ongoing and cows are starting to graze the stalks. How should this grazing be managed to get the most out of them?
One of the most important decisions in all grazing situations is stocking rate, including corn stalks. Fortunately, you can get a good estimate for corn stalks by dividing the corn grain yield by 3.5 to estimate grazing days per acre for a 1,200-pound cow.
So, for a field that yielded 210 bushels per acre, dividing 210 by 3.5 gives 60 grazing days per acre. Thus, a 160-acre field could provide 9,600 cow grazing days. That means you could graze 9,600 cows for one day or 1 cow for 9,600 days. Not very practical, so some other combinations need to be explored.
One possibility is to graze 60 cows for 160 days. Starting here at the end of October, that could take you all the way through March. Sounds pretty good but how will this work nutritionally? Cows will eat the best feed first – any downed grain and the husks. After a couple months, all that will be left are stalks and leaves that have been walked over, rained or snowed upon. Without a lot of supplements, these cows will be in very poor shape by the end of March.
Clearly, shorter grazing periods are needed. Maybe, instead of 60 cows for 160 days you graze 160 cows for 60 days. Better, but you still may need supplements near the end of the 60 days. Better still would be to give those 160 cows just one week’s worth of the stalks to start, a little over 18 acres. By day six and seven those 160 cows will have cleaned up just about everything, but on day eight you give them a fresh 18 acres, returning them to high quality feed without so much supplement.
Both stocking rate and changes in the quality of grazing with time need consideration as you plan and manage stalk grazing. Do it right and corn stalks become a great winter feed resource.
Testing for hay quality
How much did the spring and summer’s weather affect the feed value of your hay? You don’t know? Then forage test.
Nearly every bushel of corn has similar nutrient concentration, but with hay it varies considerably. Why does this happen? Well, there are many causes. For example, leafiness of the hay, or maturity of the plant when your hay was cut, or even how you handled the hay during raking and baling all can affect its feed value.
This year, weather conditions have made things more complicated. This spring’s floods and cool, wet weather caused many folks to delay first cutting or got rain-damaged hay. Leaf diseases, mature plants, and other factors made much alfalfa lower in quality. During summer we had periods of hot and very humid weather that often caused plants to burn off their easily digested nutrients at night, leaving us with hay that looks really good but is high in fiber and low in energy.
Grass hay might be even more difficult to predict. Some fields had fewer seedheads than normal. This might give higher quality hay, but if harvest was delayed in hopes of increasing yield or if the heat affected grass quality like it affects alfalfa, grass hay quality might actually be lower. And when growth is stimulated by extra rain, plants use many nutrients for increased tonnage instead of quality.
And I haven’t even mentioned all the different forages used on prevented planting acres. Different species harvested late in the year; who knows what the protein and TDN levels are like.
So you see, this year, just like always, forage testing is important. It is the only way that you can find out for sure ahead of time what the feed value is of your hay.
So gather samples now for testing, before feeding your animals and before it’s too late.
Bruce Anderson is an extension professor with the University of Nebraska-Lincoln. Reach him at 402-472-6237.