Feed costs represent the largest annual operating cost for most commercial cow-calf enterprises. In order to maintain an optimum balance between feed costs and production, feeds must be analyzed, and these analyses should be used to formulate rations and or supplements. Feedstuffs vary widely in nutrient concentration due to weather, harvest date, and other management practices.

Dry matter is the moisture-free content of the sample. Because moisture dilutes the concentration of nutrients but does not have a major influence on intake (aside from severe deprivation), it is important to always balance and evaluate rations on a dry-matter basis. On a dry matter basis, energy can easily vary ±10%, crude protein ±15%, and minerals by a much greater margin.
 
Crude protein measures the nitrogen content of a feedstuff, including both true protein and non-protein nitrogen. In ruminants, evaluation of the fraction that is degradable in the rumen, degradable intake protein (DIP), versus the rumen-undegradable fraction, undegradable intake protein (UIP), is also important. However, the rumen degradability of protein is not measured in most commercial labs. Therefore, it is recommended that rations be formulated using analyzed CP values and average values for DIP and UIP that can be found in the 1996 National Research Council Nutrient Requirements of Beef Cattle.

Crude fiber is a traditional measure of fiber content in feeds. Neutral detergent fiber (NDF) and acid detergent fiber (ADF) are more useful measures of feeding value and should be used to evaluate forages and formulate rations.

The sum of the digestible fiber, protein, lipid, and carbohydrate components of a feedstuff or diet is total digestible nutrition (TDN). TDN is directly related to digestible energy and is often calculated based on ADF. TDN is useful for beef cow rations that are primarily forage. When moderate to high concentrations of concentrate are fed, net energy (NE, see below) should be used to formulate diets and predict animal performance. TDN values tend to underpredict the feeding value of concentrate relative to forage.

By considering crude protein, crude fiber and total digestible nutrition, the feed experts at MKC can determine what supplementation program may be necessary to attain and maintain optimal condition in your cow herd. Recommendations are dependent on location, custom grind and mix, and cow supplementation. Along with programs, MKC also offers supplementation products such as; Purina Rangeland tubs, Purina Accuration tubs, Purina Accuration liquid and Purina Cattle Cubes. All of these products can be utilized alone or in addition to the supplementation program to attain and or maintain adequate body condition score.
 
To get started on the evaluation of your forages, contact MKC livestock nutrition specialists Gary Schmidt and Zoe Woolsoncroft by email at gschmidt@mkcoop.com or zwoolsoncroft@mkcoop.com. Contact Gary via phone at (785)-285-8512 or Zoe at (620)-386-4125.