There are several ways to evaluate a supplement. Cost per ton is perhaps the most obvious but the intrinsic cost factors must also be evaluated. Management from one operation to the next can vary tremendously in terms of the amount of home-raised feeds raised as well as labor and time constrains to the beef operation. Current trends indicate that the number of beef operators having a part-time job on the side is increasing with many undoubtedly finding themselves in a time pinch. Unfortunately, supplements are often purchased as a convenience item. Consequently, the manager may be unknowing over supplementing one nutrient to meet the requirements for another unless he/she custom designs or purchases a specific supplement that meets the cowherd’s requirements based on the other ingredients in the ration. Regardless of your situation, re-evaluate your supplementation program from a cost standpoint (costs due to supplemental ingredient as well as time, management, equipment, etc.) to determine if what you are presently doing can be justified.

A good place to start when evaluating protein sources is to evaluate them on a relative basis of their nutrient content. If feeds that are being compared are relatively similar in moisture content, then the following format can be used. If the moisture content of the feeds are different, then calculate the amount (pounds) of nutrient (protein) on a dry matter basis. Divide price of the feed by pounds of nutrient.

The following equation will help you compare protein supplements:

Value of nutrient in supplement = $/lb., cwt or ton of supplement % of available nutrient

For example:

Soybean meal costs $176.50/ton ($.0883/lb.) and has 44 percent crude protein. $.0883 = $.201/lb. of protein from soybean meal

.44

Dehydrated alfalfa pellets cost $108.00/ton ($.0540 lb.) and has 17 percent crude protein.

$.0540 = $.318/lb. of protein from 17 percent alfalfa pellet

.17

Alfalfa cost $80.00/ton ($.040 lb.) and has 16 percent crude protein.

$.040 = $.25/lb. of protein from 16 percent alfalfa

.16

The above calculations work well when the protein sources are assumed to be equally utilized and contain a similar amount of moisture. When NPN is included in the picture, then adjustments must be made to make the true values more realistic. In addition, the above calculation do not take into account labor, equipment, etc. to deliver the supplement to the cows.

Energy supplements may be needed in some diets. Energy levels of commercial supplements are difficult to evaluate because the levels are usually not available from the manufacturer. The best indication of energy in a supplement is the fiber level in the supplement. As a general rule, the higher the fiber in a range supplement, the lower the energy. This has changed some with the use of grain co-products like gluten feed and distillers grains because these feeds are considered high energy sources that have more fiber than the typical grain sources. Grains such as corn, ear corn, wheat, etc., are usually a cheap source of energy. Ear corn can be fed on the ground the same as range cubes, however, the cost of processing the other grains and cubing or investments in feed bunks may offset the apparent low cost. Molasses in range liquid supplements is usually not as high in energy compared to supplements containing grain or grain by-products. The sugars in molasses are digested very rapidly and are not in the rumen for a very long period of time and there is a greater amount of moisture in liquid supplements. Consequently the level of energy in liquid supplements on an as fed basis is usually lower than comparable “dry” protein or grain supplements.