Introduction

The pace of change in swine diet formulation over the past decade has been truly staggering. During the 1990’s, we successfully adopted a number of new technologies. The use of phase feeding is now almost universal. Diets are formulated on digestible rather than total amino acids, and the next step, to true digestible amino acids, appears to be just around the corner. We have a much better understanding of the relationship between whole body growth, protein/lean accretion and nutrient supply in the diet.

As important as defining nutrient requirements may be, supplying those nutrients using available ingredients must occur with the same precision. We are just beginning to understand the impact of ingredient variability, especially in energy content, on the accuracy of diet formulation; the next decade should present exciting new developments in this important area.

Finally, perhaps the most important development of the 1990’s has been the recognition that economy is as important as productivity; feeding programs are increasingly evaluated as much on the basis of cost per kg of gain, or cost per pig sold, or profit per pig space, as on days to market and average carcass index.