Genetic selection in the past has maximized lean growth, which is a problem for reproduction. Strict nutritional programs must be followed in order to ensure proper body conditioning of the sow to maintain a quality reproductive life. Gestation feeding must be done to have the best possible body condition for farrowing, lactation, weaning, and return to estrus (all of which will be reduced by a too-fat sow). Sows that are too skinny will be more susceptible to injury. Each sow should be fed to individual requirements (a body score of 3 should be target). Modern feeders typically allow for examination and adjustment of each sows daily feed amount. Conditioning should be done at breeding, 30, 50, and 80 days of pregnancy. Feed increase in the 3rd trimester should be avoided unless absolutely necessary for the sow. An efficient breeding barn requires an understanding of the pigs’ estrus cycle, signs of pro-estrus, signs of heat, and heat detection. A cycle lasts from heat to heat (~ 21 days) and the sow can only be bred during heat. During the time before heat (pro-estrus) the vulva gets red and swollen and animal riding may occur. There are many signs of heat, but the most prominent is the standing heat reflex, where the sow permits breeding. Heat checking should be done nose to nose so the boar can stimulate the sow with sound and pheromones. Boars should be housed away from the sows in order to avoid the sows getting used to them and avoid an unknown refractory period.