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Introduction to Cereal GrainsIn livestock rations, the cereal grains are one of the primary sources of energy. Cereal grains are the seeds of plants of the grass family. The cereal grains have been bred to increase the starch content of the cereal grain seed. In the U.S., the primary cereal grain fed to livestock is corn. In the U.S., other cereal grains fed to livestock to various degrees include sorghum or milo, coarse grains including barley and oats, wheat, triticale, and rye. Table 4.1 states the total and relative amount of the major cereal grains produced in the U.S. in 2001. The data are estimated data.
In the U.S. commercial market, the majority of the cereal grains are traded on the basis of bushel weight. Grains may also be traded on the basis of ton. A bushel is a set volume; the volume of a Winchester bushel is 2,150 cubic inches. To determine the test weight, the bushel is filled and the weight of the bushel of grain is measured. As the bushel weight increases, the value of the grain also increases. The system is based on the fact that the increase in density is associated with an increase in starch content, a decrease in fiber content, and therefore an increase in energy content. Grains may be valued based on grades. Grades combine bushel weight and quality measures. Examples of factors that influence the grade of the grain include presence of foreign material, antinutritional components, broken or damaged kernels, etc. Grading standards are established by the Federal Grain Inspection Service. The Federal Grain Inspection Service is a division within the United States Department of Agriculture’s Grain Inspectors, Packers, and Stockyards Administration. The following website defines the official grading standards for the grains in the United States: http://www.usda.gov.gipsa/reference-library/standards/standards.htm. Moisture is classified as a non-grade determining factor. However, as moisture influences the quality of a grain moisture levels may influence the final trade value of the grain. In general, the nutritional values of cereal grains are relatively similar
between the grains. Table 5.4 on page 61 in the text describes the average
nutrient composition of the major cereal grains. The nutrient compositions
are stated on a dry matter basis. In addition, the nutritional value of
cereal grains is relatively constant. Examples of the factors that may
influence the nutritional value of a cereal grain include the variety
of the grain, fertility of the soil, weather, and presence of pests and
disease. Figure 4.1 illustrates the general structure of a cereal grain
and the primary nutrients associated with each component. In comparing the nutritional value between the cereal grains, the most important component to compare is the energy content of the cereal grains. Table 5-13 on page 71 of the text describes the relative ME value of each of the grains for ruminants, poultry, and swine. Corn is the standard; set at 100. The energy values of the other cereal grains are stated in comparison to the energy value of corn. The majority of all the cereal grains for all the species have a lower energy value than corn. Crude protein is also used to compare the nutritional value of cereal grains. Table 5-13 on page 71 of the text describes the relative crude protein value of each of the grains for the ruminants, poultry, and swine. Corn is also the standard for the crude protein comparison. Again, corn is set at 100. In contrast to energy value, the other cereal grains have a higher relative crude protein value than corn. |
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