Journal of Animal Science, Vol 79, Issue 9 2356-2366, Copyright © 2001 by American Society of Animal Science

JOURNAL ARTICLE

Dynamic ideal protein and limiting amino acids for lactating sows: the impact of amino acid mobilization

S. W. Kim, D. H. Baker and R. A. Easter
Department of Animal Sciences, University of Illinois, Urbana 61801, USA. sungwoo.kim@ttu.edu

The limiting amino acids for lactating sows were determined using 28 primiparous sows that were intentionally underfed both energy and protein during a 21-d lactation. Groups of four sows were allotted to litter-size treatments of 6, 7, 8, 9, 10, 11, or 12 by cross-fostering as needed within 48 h postpartum. Sows were killed on d 21 of lactation. The carcass, liver, gastrointestinal tract, reproductive tract, mammary gland, and other viscera were separated, weighed, ground, and analyzed for dry matter, crude protein, and amino acids. Simple linear equations were obtained for each amino acid within tissues as a function of litter size. The mobilization of amino acids from carcass, liver, gastrointestinal tract, reproductive tract, and other viscera increased as litter size increased. Amino acids were accreted to mammary glands as litter size increased (2.65 g lysine/21 d for each one-pig increase in litter size). Milk production needs were estimated (49.9 g lysine/21 d for each one-pig increase in litter size). The quantity of each amino acid required additionally as litter size increased was obtained from the difference between amino acid needs for milk production and mammary gland growth and those provided from tissue mobilization. The relative ratio among amino acids that are required additionally (ideal amino acid pattern) was compared with the relative ratio of amino acids that can be provided from a corn-soybean meal lactation diet. From the comparison, it was shown that threonine and lysine are the first-limiting amino acids, followed by valine, when tissue mobilization occurs during lactation. Lysine is the first-limiting amino acid, and valine becomes second-limiting followed by threonine, when sows do not mobilize body tissues during lactation. Thus, the limiting order of essential amino acids changes depending on feed intake and tissue mobilization of sows during lactation. Proper feeding of lactating sows should consider the expected degree of tissue mobilization during lactation.

This article has been cited by other articles:

				S. W. Kim, W. L. Hurley, G. Wu, and F. Ji Ideal amino acid balance for sows during gestation and lactation J Anim Sci, April 1, 2009; 87(14_suppl): E123 - E132. [Abstract] [Full Text] [PDF]

				R. D. Mateo, J. A. Carroll, Y. Hyun, S. Smith, and S. W. Kim Effect of dietary supplementation of n-3 fatty acids and elevated concentrations of dietary protein on the performance of sows J Anim Sci, March 1, 2009; 87(3): 948 - 959. [Abstract] [Full Text] [PDF]

				K. T. Soltwedel, R. A. Easter, and J. E. Pettigrew Evaluation of the order of limitation of lysine, threonine, and valine, as determined by plasma urea nitrogen, in corn-soybean meal diets of lactating sows with high body weight loss J Anim Sci, July 1, 2006; 84(7): 1734 - 1741. [Abstract] [Full Text] [PDF]

				A. M. Gaines, R. D. Boyd, M. E. Johnston, J. L. Usry, K. J. Touchette, and G. L. Allee The dietary valine requirement for prolific lactating sows does not exceed the National Research Council estimate J Anim Sci, June 1, 2006; 84(6): 1415 - 1421. [Abstract] [Full Text] [PDF]

				X. Guan, B. J. Bequette, P. K. Ku, R. J. Tempelman, and N. L. Trottier The Amino Acid Need for Milk Synthesis Is Defined by the Maximal Uptake of Plasma Amino Acids by Porcine Mammary Glands J. Nutr., September 1, 2004; 134(9): 2182 - 2190. [Abstract] [Full Text] [PDF]

				S. W. Kim, R. L. McPherson, and G. Wu Dietary Arginine Supplementation Enhances the Growth of Milk-Fed Young Pigs J. Nutr., March 1, 2004; 134(3): 625 - 630. [Abstract] [Full Text] [PDF]

				J. P. McNamara and J. E. Pettigrew Protein and fat utilization in lactating sows: I. Effects on milk production and body composition J Anim Sci, September 1, 2002; 80(9): 2442 - 2451. [Abstract] [Full Text] [PDF]