^a Adapted, with permission, from Nutrient Requirements of Swine (2012), National Research Council, National Academies Press, Washington, DC.

^b Estimates of amino acid, calcium, and phosphorus requirements during gestation differ for parity 1, 2, 3, and 4+ sows, stage of gestation, body weight at breeding, anticipated litter size, and other factors. Requirements for these nutrients during lactation differ for parity 1 and 2+ sows, body weight after farrowing, litter size, and other factors. For additional information, see Nutrient Requirements of Swine (2012), National Research Council, National Academies Press, Washington, DC.

^c NE = net energy, DE = digestible energy, ME = metabolizable energy. Dietary energy contents related to corn and soybean meal–based diets. DE and ME are calculated from NE.

^d Assumes 5% feed wastage.

^e Total amino acid requirements apply to corn-soybean meal–based diets.

^f The calculated crude protein levels are based on corn-soybean meal diets containing 0.1% supplemental lysine and 3% minerals and vitamins.

^g STTD = standardized total tract digestible, ATTD = apparent total tract digestible, ATTD phosphorus and total phosphorus requirements apply to corn and soybean meal–based diets.

^h Conversions: 1 IU vitamin A = 0.30 mcg retinol or 0.344 mcg retinyl acetate; 1 IU vitamin D₂ or D₃ = 0.025 mcg cholecalciferol; 1 IU vitamin E = 0.67 mg of D-α-tocopherol or 1 mg of DL-α-tocopherol acetate.

ⁱ The niacin in corn, grain sorghum, wheat, and barley is unavailable. Similarly, the niacin in byproducts made from these cereal grains is poorly available unless the by-products have undergone fermentation or wet-milling process.