Nutrition and feed management strategies to reduce nutrient excretions and odors from swine manure.

Manipulation of the pig's diet to reduce nutrient excretions and odors is feasible and practical. Avoiding excessive dietary protein, using high quality protein sources, and feeding low protein, amino acid supplemented diets are practices that will reduce the N in excreta. Avoiding excessive overages of dietary P, balancing diets on an available P basis, and use of phytase as a dietary supplement offers potential for further reducing the P in manure. Use of reduced or organic forms of Cu, Zn, Fe and Mg will reduce excretion of these nutrients in manure. Feeding management technologies that will enhance feed efficiencies and reduce nutrient excretion include feeding for phase, sex and genetic ability of the animal. Reducing the intact protein levels in diets and balancing with synthetic amino acids, use of low levels of specific non-starch polysaccharides (NSP; soybean hulls, sugar beet pulp), and maintaining the proper acid-base balance and buffering in the diet can significantly reduce odorous compounds. Greater nutrient reductions may be possible through the development of specialty feed ingredients that will be used for specific animal diets. Research to fine-tune the diets for production systems is needed.