Interest in feeding boars to optimize semen quality and quantity and retaining the boar in the herd for a longer time have received increased attention in recent years. However, scientific research regarding the nutrition of the boar is lacking. Therefore, many feeding strategies used by commercial and private boar studs are based on a minimal amount of boar research. Experience and research that has been conducted with grower-finisher pigs is generally used to establish most nutritional requirements. Our estimates of the nutrient requirements for the growing and mature boar are presented in Table 13.