Effect of Elevated Fat and Protein Corn and Phytase on Nutrient Digestibility and Excretion in Pigs

The current concern of nutrient loading waterways and soils from livestock manure has increased awareness of methods to reduce excess nutrient excretion. The initial methods for nutrient reduction are simple diet manipulations to feed nearer the requirement of the pig. Further modifications have been made to increase digestibility of feedstuffs. The use of genetically modified corns and addition of microbial phytase are known to be effective methods for increasing nitrogen and phosphorus digestibility while reducing nutrient excretion. Two mutant corn hybrids containing the genes, Lpa-1 and Lpa-2, have 66% and 33% less total phytic acid phosphorus, resulting in greater phosphorus availability (Raboy and Gerbasi, 1996). Similar genetic selections have been made to increase protein and energy content of corn. Recently, an elevated fat and protein corn has been developed and has been combined with the low phytic acid gene to create an elevated fat and protein corn with high available phosphorus content. The objective of this study was to determine the nutrient digestibility of two genetically enhanced corns with the addition of microbial phytase when fed to finishing pigs.