Animal Nutrition Views
Dr. Ioannis Mavromichalis is an animal nutritionist holding graduate degrees from Kansas State University (MSc) and University of Illinois (PhD). He is the Principal of Ariston Nutrition Consulting International. He may be contacted at [email protected]. See all author stories and blogs.
Substitution with wheat and barley requires discussion of carbohydrases
With corn prices skyrocketing, many producers are looking into wheat and barley to slightly reduce feed cost, or at least keep it within survival limits.
When we discuss wheat and barley, we must also bring up the issue of carbohydrases, that is, enzymes that help release a bit of fiber energy. These work when such cereals are rich in hemi-cellulases, but that is hard to determine or even predict. So, most producers elect to use the enzymes anyway.
There are two schools of thought regarding the selection of the right carbohydrase to use in cereal-based diets, especially those based heavily on wheat and/or barley – the latter along with some wheat, or even corn, in most cases.
- Some nutritionists recommend using only a xylanase if the diet is based on wheat, or a beta-glucanase if wheat is absent and the diet contains high levels of barley (and the rest corn). This ensures that the target non-starch carbohydrate that abounds in the cereal present in each diet is attacked at strength and digested with the greatest efficacy, yielding the greatest benefit. This strategy appears to work best when diet composition remains relatively unchanged, which is not always the case as least-cost formulation is a must now that cereal prices are as unpredictable as weather in Kansas.
- On the other hand, there is a growing number of nutritionists that believe although wheat is predominantly rich in xylans (and barley in beta-glucans, respectively), nevertheless, all cereals contain varying levels of all non-starch carbohydrates. This is true even in the case of maize. As such, a cocktail of xylanase and beta-glucanase is believed to be more effective, especially if the cost of the enzymes per ton of complete feed is about the same in both strategies. Here, the use of cocktails would provide logistical benefits in diets with frequent formulation changes. During these times, I tend to ascribe to this thinking.
So, cereals and enzymes is a discussion we should have when corn becomes unavailable or too expensive. As always, consulting with your own practicing nutritionist is the best advice.