The connections and tensions among grain production, livestock feeding, and biofuel generation is well illustrated by conditions in Iowa during the early 21 ^st century. The traditional conditions of abundant corn may not continue in the future. It is appropriate to discuss diets based on alternative energy feed sources for swine in Iowa, the leading corn, pig, and ethanol producing state. Because starch is used to make ethanol from corn, the objective of this analysis was to explore swine diets that minimize starch usage.

Consumer demand and resultant market prices will ultimately determine whether corn is used for producing ethanol or feeding pigs. For each market pig fed a typical corn-soybean meal diet from 18–127 kg, 262 kg of corn grain is consumed. Proven diets can reduce corn use by about 30% with theoretical diets potentially lowering corn use by 45%. Typical corn-soybean meal diets use starch to supply approximately 60% of the total NE. Proven diets can reduce starch use by 26% with theoretical diets potentially reducing starch use by 45%. Although some alternative feedstuffs can be incorporated into pig diets, the feasibility of expanding their use is uncertain. Effects on pork quality, feed delivery systems, feed storage and handling characteristics, and relative economics of alternatives remain to be explored further. Using bioenergy co-products can reduce corn feeding to pigs by 25% and has the potential to reduce corn feeding to pigs by about 35% to 45%.