The most important part of winter feeding to me is not how much protein we can feed but the total calories. Protein is the most expensive nutrient and can be over fed. Too, much protein will tax the kidneys and liver while causing a G.I. upset. Mostly cattle need a certain amount of protein and then they need the calories, carbohydrates and fat. The rumen in a cow will tear apart protein and make their own. Therefore, we need to give them enough nitrogen from protein, with the building blocks from carbohydrates and fat to make what they need and to maintain or gain weight.
Most cows at this time of the year just need to maintain their weight for calving. This should be around a body condition score of 6. If your cows are below a 6 BCS, then you will need to feed more. If your cows are at a 7 BCS then feed them a little less and save the money. If you have a group of cows that are not keeping up with the herd and maintaining weight then I suggest separating them with at least a hot wire, where you can feed them some more and save the expensive feed on the rest.
Another way to maintain cows that are in good shape is to have an inventory of your hay crop. This means knowing what is your best hay, worst hay, and the middle quality. Your County Extension Service can help with this. If you are not calving until spring and your cows are in good shape, you might want to just be feeding the worst quality hay. If you need just a little boost on the cows, then just feed them the middle quality hay. Save the best hay for those that need more or for when you are calving.
In just one hay storage yard, I have seen hay testing from 10 percent to 18 percent protein. And this hay came off the same field. This also means when you sample the hay, it might take several samples to get an accurate evaluation. Also, with this knowledge you will know what type of supplementation you might have to do. Be it corn or just mineral to get the right amount of energy into your cows.
Last but not least, is the mineral program. Here at Christmas is when I recommend switching to a higher Magnesium content. Until now most of us have been feeding a 2 percent mag and normally I like switching to a 10 percent mag at Christmas. This will head off grass tetany. I have treated several grass tetany cases between Christmas and New Years. I also recommend that you use a loose mineral and only put out what the cows are going to clean up in three days. This keeps fresh mineral in front of them at all times and it doesn’t go to waste.
Dr. Tim E. O’Neill, DVM, owns Country Veterinary Service in Farmington, Ark.
