Poor cow nutrition can be economically crippling to your operation. A cow's energy status is important to her remaining productivity. Protein, minerals and vitamins are all important, but if a cow is starving, the right mineral balance is not going to help. Energy is the first priority.
A useful measure for your herd is body condition scoring. If your cows are headed into winter in poor condition their chances of rebreeding in spring are dramatically reduced. That's because it is difficult and expensive to add condition to cows during the winter, and thin cows next spring will have difficulty producing enough milk to adequately care for new calves and rebreed.
Cow body condition scoring is generally a nine-point scale, with nine being a Yield Grade 5 or obese cow that is barely able to walk. A cow scoring a one is completely emaciated and also barely able to walk. Realistically, cows on a ranch generally fall into the range of three to seven. A cow scoring a three is one that's just too thin, most of her ribs are visible, we can see her backbone in detail and she's lost muscling. She can still probably have a calf, maybe even a healthy calf, but everything else is going to drop off and suffer.
Move up to a four, we still see most of her ribs, but we can see most of the muscle structure of her round. So she's thin and carrying no excess fat whatsoever.
Five is our target. That's where we like to see cows at calving. We can maybe still see a rib or two, maybe vaguely make out the backbone, but we can see that she is carrying a little bit of body condition. At calving, if we know that she's still got just a little bit of fat, she's healthy and she's going to be able to cycle.
As we move into the sixes, we really can't even see the muscle anymore. She's just covered with a thin layer of fat, very healthy and productive. Once you move to a seven, you're wasting energy and feed. She's got fat deposits around the tail and in the brisket.
You should expect any threes and fours to be late breeders next summer or possibly open next fall. Those thin cows also are more likely to have lighter weight or possibly sickly calves.
Fortunately, too many threes and fours in your herd is correctable. If you have the facilities, separate your thin cows and feed them differently than the cows that score five or six. If your thin cows are young, that means they are still growing and part of their energy consumption is going to frame growth and muscle. If they're older, give them a little extra care and get another calf out of them, then make your decision.
If you need to move cows up in body condition score, say from three to four, or four to five, we generally think of adding 100 lb. to their weight. That can't be done overnight. Realistically, adding a pound per day to a bred cow during the winter will require extra energy, a cost that might prove worthwhile if she weans a big, healthy calf next fall. Supplementing with byproducts, distillers' grains, gluten feed and other fibrous feeds are an excellent energy source.
Failing to erase the threes and fours from your herd, however, will have an impact on immune status, neonatal calf scours and colostrum quality‚Äîall factors that will reduce your income next fall.
Dan Thomson, DVM, Ph.D., is a professor of production medicine and epidemiology at Kansas State University's College of Veterinary Medicine. You can contact him at:
Note: This story appears in the November/December issue of Drovers.