A guide to fine tuning a diet formulation

It is obvious that if commodity prices and qualities remain stable in combination with never changing nutritional needs of animals, a fixed diet formula could be sufficient. But we all know, this is not practice. Market prices are unsteady and new insights on animal requirement differ around the world. How can we deal with this effectively? If we would all stick with the fixed formulas, supplying the feed producers with commodities would be easy as pie. Unfortunately this is not the case. One o