Corn gluten feed is a byproduct of the wet milling of corn to produce cornstarch, sweeteners, oil and other products. Corn gluten feed (CGF) is typically a combination of corn bran, corn germ & steep liquor. Corn Gluten available in either wet or dry forms is generally palatable and readily digested by cattle. Dry CGF is available as meal or pellets
Animal feed needs to meet the requirements of the animal. For cattle, it must contain a certain structure to keep the stomach healthy, and for all animals, it must contain dry matter, various groups of nutrients, minerals, and trace-elements and should not be moldy or mixed with dirt and soil nor contain poisonous ingredients (for example pesticides or herbicides on crop residues). The composition of feeds in a ration depends on the type of animals being fed and their stage of production. Cattle and goats, being ruminants, are better equipped to digest crude fiber than pigs or chickens. Young animals need more protein than adult animals, while animals in milk need higher protein content in the ration than non-lactating animals.
Generally, animals must have a ration containing:
· Energy (from carbohydrates and fats) to maintain the body and produce (milk, meat, work). The carbohydrates and fats not needed for production are converted to fat and stored in the body.
· Protein is needed for bodybuilding (growth) and maintenance as well as milk production. Without protein, there would be nobody weight gain nor milk production. Excess protein is converted to urea and fat
· Minerals help in bodybuilding as well as in biological regulation of growth and reproduction. They are also a major source of nutrients in milk.
· Vitamins help regulate the biological processes in the body and become a source of nutrients in milk
· Water helps all over in bodybuilding, heat regulation, biological processes as well as a large constituent of milk production as well as eggs.
While corn gluten feed is derived from corn, the nutrient levels are generally higher than for corn since the ingredients remaining after processing have been concentrated. The crude protein content of CGF is somewhat variable, as would be expected since the protein content of corn itself is variable. Crude protein values range from 16 to 23 percent, with the lower numbers most common in Tennessee.
The most-used term to describe the energy level in a diet is “TDN,” which stands for total digestible nutrients. The TDN value of CGF is generally around 80 to 83 percent. This is lower than corn (88% TDN), but the form of energy is different. Corn is high in starch while CGF is low in starch. Since starch decreases the activity of the rumen microbes which digest fiber, feedstuffs like CGF, which are moderately high in energy from digestible fiber, are a good “match” for high forage diets.
Corn gluten feed can be an economical source of nutrients. The protein and energy provided by a hundred pounds of dry CGF (90 percent DM) are roughly equivalent to 75 pounds of corn grain plus 25 pounds of Soybean meal (48 percent CP). The best method to get a fair comparison between CGF and other feeds is to incorporate these in rations formulated on a “least cost” basis. Computer programs are available for this.
Storage facilities also need to be considered. Dry CGF can be stored in grain bins; however, wet feeds require storage in a trench, bunker, bag or wet commodity storage pit. Wet CGF should be used as quickly as possible and stored in a manner that reduces spoilage, especially during the summer.
The mineral content of the CGF is to be checked beforehand to avoid mineral imbalances due to high levels of phosphorus, potassium, and sulfur. Of these, possibly the most serious problem is with sulfur, which routinely reaches 0.5 to 0.6 percent and sometimes higher, particularly in the wet product. This may limit the amount which can be used to about 0.5 percent of body weight (dry matter basis).
The high phosphorus but relatively low calcium content could result in calcium to phosphorus imbalance, particularly if CGF is fed above the recommended level of 0.5 percent of body weight. These limitations have often led producers to blend CGF with other feedstuffs, like corn and soybean hulls.
