The digestible energy value of wheat for pigs, with special reference to the post-weaned animal [Review]

Wheat used in pig diets has variable physical characteristics, such as bushel weight and contains variable quantities of nutrients and anti-nutritional factors due mainly to the genetic and environmental influences the crop encounters during growth. However, variations in physical and chemical characteristics are not generally considered when wheat is used in the formulation of pig diets. This review aims to illustrate the variation in wheat quality that occurs, with most focus on the digestible energy (DE) content since the major purpose of wheat in pig diets is as an energy supply, and to address factors influencing the variation of energy value, with special reference to weaner pigs. The factors discussed in this review include physical and chemical characteristics, variety, growing region, season, post-harvest storage, the use of supplemental enzymes, such as xylanase and phytase, age of pigs and processing of grains.