118 Awardee Talk: An Empirical Model of Essential Amino Acid Requirements in the Pregnant Sow

Abstract

Abstract Amino acid (AA) requirements are generally considered to be the minimum needed for maximum growth or protein synthesis; however, multiple studies have shown that AA intakes above these requirements improve various body functions such as immune response, gut health, and reproduction. The objective of the current modeling approach was to estimate AA intake in gestation that considered protein synthesis as well as sow reproductive performance and offspring development, potentially increasing piglet growth and survivability. A literature review was conducted to identify studies evaluating the effects of sow AA intake during gestation on protein synthesis, sow body weight, litter size, average piglet birth weight and suckling piglet growth rate. Data from 26 empirical studies from 1989 to 2021 were selected for model development and estimation of arginine, leucine, lysine, methionine, threonine, and valine requirements. To check model accuracy and performance, a validation analysis was conducted by contrasting the model predicted lysine requirements with data from 17 published studies not used in the development of the model. The estimated lysine requirement was approximately 40% greater than the minimum lysine intake required for maximum protein synthesis. Similarly, the ratios of arginine, leucine, methionine, and valine to lysine were on average 1.60, 2.47, 0.41, and 0.79, respectively, which are 6 to 300% greater than, and the ratio of threonine to lysine was similar to, current recommendations. The validation analysis showed that the estimated lysine requirement resulted in the greatest litter size and birth weight. In addition, when compared with lysine intakes that met current recommendations, lysine intake at the estimated requirement improved colostrum and milk quality, stillborn rate, proportion of low birth weight, suckling piglet growth rate, and sow blood urea, among other metabolic variables. In conclusion, at the estimated requirements sow reproductive performance as well as piglet survivability and growth rate are improved.