Using Low-quality Roughages
in Late-gestation Rations

by Warren Rusche, South Dakota State University

Most spring-calving cow herds are now in late gestation, or will be very soon. This is one of the more critical times on the calendar in terms of optimizing herd productivity. Not only is the bulk of fetal development occurring, but it is also our last realistic chance to put body condition on cows.

Most years, feeding a beef cow herd in the winter is relatively straightforward. We put up hay all summer and feed it all winter. Most years there’s enough good-quality hay to go around. The economics of relying on harvested feed may be an issue, but at least from a standpoint of feed availability and nutritional adequacy, that system has generally worked well.

The drought of 2012 has turned that system on its head. Good-quality grass hay and alfalfa hay is scarce and extremely expensive. Beef producers will be forced to be more creative in their feeding programs, and in many areas that means feed such as salvaged cash-grain crops, low-quality roughages and byproducts.

While it may not be as simple as just feeding high-quality grass and/or alfalfa hay, late-gestation diets containing the above types of feedstuffs can certainly be created and made to work very well. The first step, however, is to get a representative sample of the forages taken and analyzed. Some of the early test results have shown Conservation Reserve Program (CRP) hay in South Dakota to be as high as 9% and as low as 2% crude protein (CP), depending on harvest date and prior field history. Corn silage results have ranged from 6% to 11%. Relying on book values when compositions are that variable could prove to be disastrous, either in terms of animal performance or a producer’s pocketbook.

After the nutrient values are known, then a diet can be developed. A couple example rations for a 1,400-pound (lb.) cow in late gestation are shown in Table 1. In some cases, some additional protein supplements may need to be used, or a smaller amount of higher-quality roughage is needed to balance out the various silages, crop residues and other roughages. The exact answer will depend on the resources that each operation has available or that can be purchased economically. These rations should be viewed as ideas or suggestions; an exact feeding program will depend on the conditions at each feeding scenario.

For some of these rations, particularly those relying on corn silage, the amount of dry matter offered may not be enough to completely satisfy the cows’ appetite, even if the amounts of energy and protein are sufficient. In those cases, making sure that every cow has an equal opportunity to consume her daily ration will be very important to make sure that the less dominant cows don’t lose condition. Another strategy that has been successful when limit-feeding cows has been to allow the cattle access to relatively cheap roughages, such as cornstalks, whether that is through grazing or in a bale form. For more information about limit-feeding strategies, check out the iGrow article Strategies to Control Hay Intake and Waste.

For more information feel free to contact SDSU Extension Cow-Calf Field Specialist Warren Rusche or your nearest SDSU Extension cow-calf field specialist.

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