Pluses and minuses of alternative feed ingredients
Consideration of the benefits and drawbacks of alternative ingredients is essential before embarking on any substitution strategy.
The cost of almost all feed ingredients, especially corn, soybean meal, phosphate, fat and even vitamins reached record levels in 2008. Various factors lie behind these increases, and their respective impacts have been widely debated. What is certain, however, is that the massive diversion of feed ingredients to biofuels, lower crop yields in some areas and growing demand for animal proteins from developing countries have all contributed to push prices higher.
Whenever feed costs cycle upwards, interest increases in the feasibility of using alternative ingredients. Even though grain prices have eased down from record levels, they are still relatively high and interest in alternatives is currently strong.
What exactly constitutes an alternative ingredient is also an open question. To some in the feed industry, any energy or protein source other than corn, soybean meal and fat is taken to be an alternative.
A better working definition of alternative ingredients would be those that:
- have not previously been used on a regular basis;
- whose nutrient composition has yet to be fully defined; or
- for which maximum levels of inclusion are unclear.
There are very few materials of either plant or animal origin that have not been tried as feed ingredients.
This is not to say that new ingredients do not occasionally arise, although any such ingredient is usually available in limited supplies only, and on a local basis. It is safe to assume that there are few, if any, industrial quantities of a previously unknown ingredient ready for immediate purchase.
Additionally, the abundance, and generally favorable pricing of corn and soybean meal have resulted in a situation where, despite extensive research, there has been little actual demand for alternative ingredients.
In the Southeastern USA, for example, cottonseed meal, peanut meal and local wheat are all deserving of further consideration. Other alternative ingredients that may not have been fully considered in the past are the byproducts of the biofuel industry, catfish meal and pearl millet.
Others, such as bakery and animal protein meals, are now so widely used that they can no longer truly be called alternative ingredients.
The feed industry may be familiar with most alternative ingredients. Their respective nutrient compositions have been established. However, there is a further complication when considering alternatives.
Alternatives tend to be produced in relatively small facilities, with variations in manufacturing procedures. A common result is that the same ingredient may vary markedly in nutrient composition when procured from a variety of sources.
A prime example of this variation is dried distillers grains plus solubles (DDGS), which is currently produced at more than 120 locations worldwide. The protein content of meals from these plants varies from less than 26% to over 29%. If variations of this magnitude were to exist in soybean meal, the high and low protein samples would not be sold as the same ingredient.
While the nutrient composition of most alternatives is known, anyone considering their use should request samples from suppliers to properly evaluate an individual ingredient's nutrient profile.
Almost all ingredients have an "Achilles' heel," or some aspect of their composition that demands the attention of the nutritionist prior to use. In the case of sorghum, for example, this might be tannins, for feed fats oxidative stability, MIU (moisture, impurities and unsaponifiables) and possible residues, and for corn mycotoxin contamination.
The maximum level of inclusion of alternative ingredients is, to a large extent, based on such considerations, along with actual determined nutrient composition.
Cottonseed meal, for example, contains gossypol, which can discolor the interior of eggs. This obviously precludes its use in laying hen feeds. Sources of cottonseed meal with low levels of gossypol can be successfully used in broiler diets and pullet feeds, but such inclusion is likely to be limited by the low content of both total and available lysine.
Peanut meal is also low in lysine, but additionally carries a risk of aflatoxin contamination. However, when purchased from a reputable supplier, peanut meal can be a valuable ingredient, as it is high in energy, protein and the essential amino acid arginine.
Alternative ingredients should always be considered for use in feed formulas, not only at times when the price of more standard ingredients is high.
It is questionable whether significant savings can be achieved through the use of alternative ingredients and, while economically beneficial special relationships can, at times, be developed with suppliers, prices of ingredients with a similar nutrient content almost always rise and fall in tandem.
The unfortunate reality of alternative ingredients is simple: there are no inexpensive trainloads of either a new grain in Manitoba, or an undiscovered oilseed in Mississippi.