Are You Over-feeding or Under-feeding Your Cows?

Return to Crops and Livestock Agent Articles

Like most answers on the farm, it depends. One of the biggest factors is what stage of production your cows are in. If you have some cows that calf in the fall, they are at the highest stage they ever will be for their nutritional requirements. She just had a calf, is milking heavily and will shortly need to get her body cycling to re-breed. She needs a lot of groceries, and a lot of protein and energy.

If, on the other hand, you have a cow that calves in the spring, she may be at the lowest nutritional stage of her production cycle. During this time, until about 90 days away from calving, she can get by on lower quality forages, and has one of the lowest needs for protein and energy.

Feed Quality

The second biggest factor to consider is what your cows are eating and do you know the quality. There are “book values” for forages and grains, and this is a good way to get a ballpark for nutritional value. But if you really want to know, and this is especially important for forages, take a forage sample and have it analyzed. The resulting moisture content, protein value, fiber content and calculated energy values will help you know just how much to feed.

Without making a short article too long, don’t forget to keep in mind weight of your cows, their body condition, weather and other stress factors. These will certainly play a factor in whether to feed a little more or a little less.

Calculating Feed Quality and Quantity

But given the stage of production and the quality of your hay, let’s do a quick calculation. If I don’t plan to calve until next March, then right now my cows need about 1.4 pounds of protein a day and 9.5 pounds of total digestible nutrients (TDN). If I’m feeding an average quality brome of fescue hay (let’s say 7% protein), my 1,100 pound cow will eat about 2% of her body weight in dry matter, or 22 pounds. If I multiply 22 pounds times 7%, she should be getting a little over 1.5 pounds of protein a day. That meets her needs right now without any protein supplementat

But what happens if this is a fall-calving cow? Instead of needing only 1.4 pounds of protein a day, she jumps up to 2.3 pounds per day. All of a sudden, feeding brome hay isn’t enough. Even though she will eat more, there’s probably not enough nutrition in the grass hay. Now is the time to feed additional protein and energy in the form of alfalfa hay, a protein supplement, or a grain and protein supplem

This isn’t rocket science, by any means, because if it were I wouldn’t be able to figure it out. But these basic calculations are something you need to think about, especially if you have mixed production herds. And the great news is, there is a publication we have had around for years that can help guide you. The Beef Cow Nutrition Guide is available. Read through the publication and it should give you some handy facts. If you need a little help, give me a call and we’ll do some math together.