Many livestock farmers are looking for ways to replace common soybean meal to lower feed costs. This animal feed ingredient staple has become so expensive that alternatives are urgently sought after by livestock producers, nutritionists and feed companies.
Before contemplating on how to replace soybean meal, make sure that its use is already minimized through diet formulation. This implies lowering protein and amino acid safety margins and ensuring protein is not wasted beyond what is required to meet animal requirements. Using the correct amino acid profile (lysine to other amino acids ratios) usually lowers total amino acid specifications, which lowers feed costs. Dietary lysine specifications are often at least 10 percent higher than required in most formulas that I have reviewed, and this is another way to control feed cost before replacing soybean meal.
Soybean meal alternatives
Once the decision to look for soybean meal alternatives has been reached, there are three points that need to be considered beyond protein and amino acid levels. These include digestibility, taste and anti-nutritional factors.
Amino acid digestibility can widely vary among different protein sources. For example, in cottonseed meal, lysine digestibility is around 55 percent compared to over 88 percent in soybean meal. Using true ileal digestibility values instead of total amino acid concentrations is highly recommended when introducing novel ingredients in a typical diet currently based on soybean meal. Cottonseed meals' very dry nature makes it less palatable than soybean meal, especially when used at levels exceeding 10 percent. This can be resolved by adding some extra oil in the diet, but this implies a higher final feed cost that must be taken into consideration.
Finally, any low-cost alternative protein source will contain at least the same level of anti-nutritional factors found in soybean meal. However, some of these may be of a different chemical nature. Most alternative protein sources contain more anti-nutritional factors than soybeans, with few notable exceptions such as dehulled sunflower meal.
There is no easy way to compare an alternative protein source to soybean meal. Once the above concerns are addressed and a maximum inclusion level is established, then the “opportunity” price for the alternative protein source can be established through least-cost reformulation of a diet.
Introducing new proteins in feed
When switching to a less-expensive feed protein source, start by using only half the recommended maximum inclusion level so any unforeseen problems in quality can be quickly rectified. It is best to start using the alternative protein source in the diets of gestating sows and finishing pigs before attempting any soybean meal replacement in lactation and starter formulas.
It must be stressed that soybean meal remains one of the most attractive protein sources despite its higher price. Depending on feed prices, lower animal performance might be acceptable by using alternative protein sources. However, such protein alternatives are best decided with the help of a qualified nutritionist with experience in “exotic'” animal feed ingredients.