![]() |
|
|

Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada T6G 2P5;
* The Rowett Research Institute, Aberdeen, Scotland, UK;
Department of Surgery, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada L8S 4L8; and
** Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1
3To whom correspondence should be addressed. E-mail: cdelange{at}uoguelph.ca.
Inevitable catabolism contributes to the inefficiency of using dietary lysine intake for body protein deposition (PD). This study was conducted to determine the effects of true ileal digestible (TID) lysine intake, body weight (BW), and growth potential on lysine catabolism in growing pigs. Starting at 15 kg BW, 16 female Yorkshire pigs were offered a purified diet providing all nutrients in excess of requirements for maximum protein deposition (PDmax). At
25 kg BW, the pigs PDmax was determined using the N-balance method. Thereafter, 4 pigs were allocated to each of 4 diets, first-limiting in lysine, providing lysine intakes corresponding to 60, 70, 80, and 90% of estimated requirements for PDmax. The pigs were surgically fitted with catheters in the jugular and femoral veins. Lysine catabolism was determined at 2 BW (4045 kg, low; 7075 kg, high) either directly (oxidation) using a primed, constant infusion of L-[1-14C]-lysine or indirectly (disappearance) using the N-balance method. There was no effect of BW on the rate (g/d) or fraction of TID lysine intake catabolized. Lysine catabolism decreased with increasing growth potential. Lysine disappearance and lysine oxidation (% of TID lysine intake) were independent of lysine intake, except for the lowest lysine intake level, where they were lower. When lysine catabolism was independent of intake, lysine oxidation based on plasma free lysine specific radioactivity (SRA) was lower (9.9% of TID intake) than lysine disappearance (17.4% of TID intake) or lysine oxidation based on liver free lysine SRA (13.4% of TID intake).
KEY WORDS: protein deposition nitrogen balance lysine intake lysine catabolism lysine oxidation
This article has been cited by other articles:
![]() |
R. O. Ball, K. L. Urschel, and P. B. Pencharz Nutritional Consequences of Interspecies Differences in Arginine and Lysine Metabolism J. Nutr., June 1, 2007; 137(6): 1626S - 1641S. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. F. Bertolo, S. Moehn, P. B. Pencharz, and R. O. Ball Estimate of the variability of the lysine requirement of growing pigs using the indicator amino acid oxidation technique J Anim Sci, November 1, 2005; 83(11): 2535 - 2542. [Abstract] [Full Text] [PDF] |
||||