Alternative feeds for feedlot cattle
by Allen Trenkle, department of animal science, Iowa State University
Edited by Eileen Ringnalda, extension
communications.
Cattle feeders should always be aware of the opportunities to utilize alternative feeds that reduce costs of production. With high corn prices in 1996, using alternative feeds is one way to lessen feed costs.
Factors to consider
One of the first considerations when looking at an alternative feed is whether the byproduct is safe and if cattle will consume the feed. Some byproducts may contain harmful materials that are toxic or inhibit consumption. Nutrient content in relation to the requirements of cattle also should be considered. For example, high protein feeds will have more value when fed to cattle with greater protein requirements. On the other hand, fibrous feeds with lower digestibility are not reasonable options for replacing corn in a finishing diet.
Some byproducts are wet materials which will increase cost of transportation, cause problems with storage, and require a change in feeding methods. Price of the alternative feed should result in lower feed costs. A final consideration is to check for the availability of nutrients in the byproduct being considered. When the decision is made to utilize a byproduct, the supplementation of the ration should be altered to account for the addition of the byproduct.
Because corn gluten feed is available in many parts of Iowa and has been well researched as a feed for cattle, it will be used as an example for evaluating use of alternative feeds in cattle rations. Corn gluten feed (CGF) is a coproduct of the wet corn milling industry and is available in wet (40 to 60 percent dry matter) or dry (90 percent dry matter) forms. CGF is palatable and readily consumed by cattle. Though CGF is a fibrous feed (8 to 10 percent crude fiber), the fiber is highly digestible, resulting in a feed with energy similar to corn grain in feedlot rations. It is estimated that the energy of wet and dry CGF is 95 percent and 90 percent that of corn.
Protein concentrations vary between processing plants, but usually average about 21 percent on a dry basis. CGF also contains high concentrations of phosphorus, potassium, and sulfur. It has very low concentrations of calcium. The high sulfur content may be a problem in certain situations and may require supplementation with thiamin. As CGF in the diet increases above 30 percent of dry matter, it is important to make adjustments to account for changes in fiber, calcium, and sulfur.
Research results
Numerous feeding trials have shown that wet or dry CGF can be used to replace part of the corn, some roughage and corn, or all the roughage and some corn in feedlot rations without significantly changing performance, dressing percent, or carcass value of finishing cattle. Typical results are shown in table 1.
Potential benefits
The economic benefits from feeding wet CGF are shown in the figures. All results are calculated for 740 lb. steers fed a control diet containing 69.8 percent corn, 21.3 percent corn silage, 6 percent soybean meal, and supplement for 165 days (1,300 lbs. final weight). The price of CGF was compared with corn on a price per pound of dry matter at 100, 90, and 80 percent price of corn.
Table 1. Results of feeding steers corn gluten feed.¹
| Control | Ration 30% wet CGF | 30% dry CGF | |
|---|---|---|---|
| Gain, lbs/d | 3.12 | 3.22 | 3.39 |
| Feed/day, lbs | 21.3 | 21.4 | 22.8 |
| Feed/gain | 6.83 | 6.66 | 6.73 |
| Dressing percent | 63.3 | 63.9 | 63.2 |
| Percent Choice | 94.4 | 88.9 | 94.4 |
¹740 lb. steers fed a corn-based ration containing 21.3 percent corn silage on a dry basis. Wet or dry CGF replaced 10.7 percent of the silage, 18.1 percent of the corn, and all supplemental nitrogen, phosphorus, and potassium.
Figure 1. Benefits from replacing corn with 30% of diet as corn gluten feed.¹
¹Silage price increased $5/ton with each $1 increase in corn price. Remaining feed prices remained constant.Three CGF prices as percent of corn.
Figure 2. Benefits from replacing corn with 30% of diet as gluten feed.¹
¹All feed prices increased with corn and CGF. Three CGF prices as percent of corn.
Figure 3. Benefits from feeding corn gluten feed.¹
¹Broken line: Except for corn and CGF, ingredient prices constant. Solid line: All ingredient prices increased with corn and CGF. CGF priced 90% of corn on dry basis.
Figure 1 compares the benefits of feeding CGF at different prices of corn and CGF when the price of corn silage increased $5/ton for each dollar increase in corn, and cost of supplemental ingredients were held constant. There were greater benefits from feeding CGF when it replaced relatively high priced supplemental ingredients at low corn prices. As corn and CGF prices increased, cost of supplement made up a smaller share of total feed costs and there was less benefit from feeding CGF.
Benefits of feeding CGF, when all ingredients increased in price relative to corn, were greater with higher feed prices (figure 2). Figure 3 shows the benefits of feeding CGF when corn is replaced by 30 percent CGF, when corn and some silage is replaced by 30 percent CGF, or when all the silage and some corn is replaced by 60 percent CGF. Prices of ingredients other than corn and CGF were held constant or allowed to increase in proportion to the price of corn. Greater benefits were obtained when CGF replaced corn rather than replacing some or all the silage.
The results shown in the figures indicate that economic benefits from feeding CGF are greatest when used to replace high cost ingredients such as supplement. If more than 30 percent of the diet as CGF is fed, economic returns will be less. No benefits are derived from the protein and minerals in CGF when fed above 30 percent of the diet.
If input of feed costs are in relation to cost of corn, excellent returns could be expected if cost of CGF is equal to or less than cost of corn when compared on a dry basis. If costs of roughage and supplement are held constant, then returns from feeding CGF will decrease with an increase in price of corn and CGF. The cost of CGF should include transportation and any loss with storage. The cost of corn should include processing and transportation if purchased.
Other alternative feeds
Other potential sources of feed energy for finishing cattle when priced competitively with commonly used cattle feeds include the following:
Other commodity grains—These include all other grains that might be alternatives to high-priced corn. Out of condition grains can be included in this list. Commodity grains should be used in finishing diets based on chemical composition and energy value related to corn.
Grain screenings—Available wherever grain is cleaned. Feeding value will be near that of the clean source of grain. Determine value based on composition to account for debris.
Distillers grains with solubles—Dry distillers grains is available as a commodity feedstuff. It has highest value as a source of supplemental protein. Wet distillers grains with solubles from corn or milo is an excellent cattle feed with an energy value about 1.2 times that of corn grain. Distillers grains can be derived from corn, milo, wheat, or any grain being fermented.
Distillers solubles—Condensed solubles from grain alcohol plants. This alternative feed may contain over 70 percent water. It has value as a source of energy and protein.
Brewers grains— Similar to distillers grains, but it comes from the brewing industry and may include several grains, especially barley.
Condensed steep water—Available from wet corn milling plants. It is usually combined with corn bran to make corn gluten feed. Condensed steep water is a good source of protein and energy. It has been combined with whey to result in a high energy liquid feed for cattle.
Wheat milling byproducts—The most common would be bran, the coarse outer coat of wheat, and middlings which may contain bran, endosperm, and germ. These are high-fiber feeds, but very digestible. The energy value for cattle can be similar to corn if properly fed.
Soy hulls—The coarse outer coat of soybeans removed in processing soybeans. They are high in fiber, but highly digestible and therefore relatively high in energy for cattle.
Cannery, vegetable, and fruit wastes—These are seasonal sources of feeds for cattle which can be stored.
Bakery byproducts—Materials from bread, cookies, cakes, crackers, flours, doughs, and candy are available. They are fed primarily as sources of energy, but they also can supply significant amounts of protein or minerals.
Fats and oils—Depending on price, they may be an economical source of energy.
Animal wastes—Animal and poultry manure may be sources of nitrogen, minerals, and energy for cattle if they are properly treated and stored. Paunch contents from beef packing plants has been used as feed for cattle, but it is variable in composition and difficult to store and feed.