It is the time of year to be thinking about winter or at least preparing for it. So what should we be thinking about? We’ve discussed some of these before, but friendly reminders are never bad.
Balance Livestock with Forage
It is a good idea to evaluate and balance grazing livestock with available feed. To do this, take the different classes you have (cows, heifers, stockers, ewes, etc.) and figure an average weight per class and then multiply that number times the number of each class. Now you have a total live weight. Multiply that by .03 to get an average daily intake.
For example 20 cows weighing 1,100 pounds is 22,000 pounds live weight times .03 (three percent dry matter intake) equals 660 pounds of dry matter needed per day.
Now what are you going to feed those animals? It could be stockpiled forage, crop residue, hay, supplements, or most likely a combination of these. Stockpiled forage is usually going to be tall fescue with some other grasses and legumes mixed in. You can lay a clipboard on top of the standing sward and then measure the height of the compressed forages to estimate it. If the stand is pretty dense, then there is usually about 300 pounds per acre inch of dry matter. So, if you happen to have 10 inches that is 3,000 pounds of dry matter per acre. You do not want to remove it all, so let’s say you remove six inches; that is 1,800 pounds available for grazing times the number of acres of this stockpiled forage. Fields do vary, adjust as needed.
The efficiency of grazing rescue will depend on how you allocate it out. If you let stock have the whole field then expect 60-75% utilization, at best you’ll have 1,800 pounds available per acre. If you allocate it out like you are feeding hay using temporary fence to give them one or two days’ worth at a time, you’ll find the efficiency to be up near 90 percent. In areas with plenty of moisture, the stockpiled fescue is good quality and quantity this fall and will provide a lot of good grazing.
How’s Your Hay Supply?
Inventory any hay you have on hand. You should have an idea how much bales weigh and how many you have of each. For example, if you have fifty 1,500 pound bales (about 1,300 pounds dry matter) on hand, you essentially have 65,000 pounds available.
The efficiency of this hay is also dependent on how you feed it, plus how it is stored. The worst case scenario is hay fed free choice without any feeder structure and hay stored outside on the ground which sadly wastes about 45% of the offered hay. Feeding enough hay for only 2-3 days at a time creating some competition between cows, in ring or cone type feeders and storing bales inside is pretty efficient with an average of about 15% waste….that is, assuming that the hay is good quality too. Small bales, fed in feeders, are probably the most efficient, but certainly a little more labor intensive and just not used as often as in the past. If you have silage or balage on hand to feed, figure it into the plan and generally expect 90% efficiency adjusted to dry weight.
How Good is Your Corn Residue?
The nutritional value of corn stalks can certainly vary from year to year. Stalks will start out in the 8% crude protein range with approximately 70% total digestible nutrients (TDN) and over a period of about 60 days drop to 5% crude protein and 40% TDN. Spring calving cows will meet most of their energy needs during mid gestation. Growing animals such as calves and fall calving lactating cows may be lacking some in energy and protein and most likely will need to be supplemented if run on stalks.
About one acre of typical corn residue will be needed per animal unit per grazing month. Weekly allocations seem to work very well so you need to figure how many acres of stalks will be needed for one week of grazing for your herd. Higher yielding corn certainly produces more residue and more potential grazing. You can usually bank on about 12-15 pounds of desired residue to graze per bushel of corn. Compare the amount of dry matter you will need for the livestock with how much you have. Now you know about how much dry matter you are going to need to get them through the winter and an idea on how much you have available to feed them. If you are a little short on forages, you can add some supplements such as corn gluten, soybean hulls, etc. into your feeding plan. In fact, you may want to anyway if hay quality is somewhat lacking, or if more energy is needed. We used 3% for the intake estimate which is actually a little high, but if we have a wet, cold winter, energy needs to keep warm will increase and any growing animals will also have higher needs. It’s better to overestimate than to be short. Cold, wet, and especially muddy conditions will increase energy requirements. If you are still short on feed, then you may want to purchase some hay or consider reducing numbers some.
We will also soon have our first frost; some areas already have. Summer annual warm-season grasses; such as sudangrass or sorghum-sudangrass hybrids, and johnsongrass produce a cyanide compound when frosted and quickly starts shutting down, causing the production of the prussic acid. To be the safest, livestock should be removed from these forages for at least two weeks to allow for the forages to “dry down” and the prussic acid to dissipate before grazing again. These forages can be harvested for balage right after being frosted and later fed as long as they are allowed their normal fermentation process time period of three or four weeks. Frosted areas could be only “pockets” in a field to start with. Any regrowth from the base of the plant after a frost can also be very high in prussic acid.
This fall in Indiana, there are also quite a few corn fields that look like they have a corn cover crop. This volunteer corn has potential to be good for grazing, especially along with corn residue. It wouldn’t be a lot different than a planted winter annual except there is slightly more risk of nitrates, especially where yields were poor. Grazing volunteer corn after being frosted could cause bloat, especially if grazed right after the frost. Probably best to remove livestock until it dries down after that frost to play it safe. If in doubt about nitrates or prussic acid – test before feeding or grazing!
Lastly today, if you haven’t checked your winter feeding pads, it would be better to do that now while the weather is still good and add more lime topping or aggregate as needed. Also, not a bad idea to take the time to double check winter watering tanks while the weather is still good.
Keep on grazing!