Response to lysine in a wheat gluten diet in adult minipigs after short-and long-term dietary adaptation as assessed with an indicator amino acid oxidation and balance technique.
An experiment was conducted to examine the response to wheat gluten (WG)-based diets at two lysine levels in adult minipigs (23 kg BW) using the indicator AA oxidation (IAAO) approach and N balance. Twenty minipigs (n = five per group), fitted with reentrant ileoileal cannulas allowing collection of ileal effluents, were fed restrictively two WG-based diets (WG and WG + Lys; 2.7 and 6.6 g of lysine/kg, respectively) for adaptation periods of 10 and 100 d. On d 7 and 9, for pigs fed the diets for 10 d, and on d 97 and 99, for pigs fed the diets for 100 d, primed i.v. fasted/fed tracer protocols with [(13)C]bicarbonate, and [(13)C]leucine were performed. With the WG diet, [(13)C]bicarbonate recoveries (%) were lower irrespective of the adaptation period, and higher during the fed period (fasted: WG + Lys = 82.5, and WG = 69.1; fed: WG + Lys = 90.6, and WG = 85.9; P < 0.05). Leucine oxidation rate was higher with the lower lysine intake (WG = 194.6 vs. 109.5 mg/[kg BW x d]; P < 0.05). Wheat gluten feeding resulted in a negative leucine balance independent of the adaptation period (WG = -29.1, and WG + Lys = 48.2 mg/[kg BW x d]; P < 0.05). In contrast with the IAAO method, N balance did not differ between the two lysine intakes, possibly because of an underestimation of N losses. The finding of a lower (13)C bicarbonate recovery with the lower dietary lysine intake suggests that caution should be taken in using a single recovery factor for all AA oxidation studies.
Metges
C C
CC
Research Unit Nutritional Physiology, Research Institute for the Biology of Farm Animals (FBN), 18196 Dummerstorf, Germany. metges@fbn-dummerstorf.de
Petzke
K J
KJ
Backes
G
G
Elsner
A
A
Junghans
P
P
Derno
M
M
Nürnberg
G
G
Hennig
U
U
D000818:Animals; D001639:Bicarbonates / Q000378:metabolism; D002250:Carbon Radioisotopes; D004032:Diet; D005215:Fasting / Q000502:physiology; D005983:Glutens / Q000008:administration & dosage*; D007930:Leucine / Q000378:metabolism; D008239:Lysine / Q000008:administration & dosage* / Q000097:blood / Q000378:metabolism*; D008297:Male; D009584:Nitrogen / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects*; D011849:Radioactive Tracers; D013552:Swine; D013556:Swine, Miniature; D013997:Time Factors; D014908:Triticum
D001639:Bicarbonates; D002250:Carbon Radioisotopes; D011849:Radioactive Tracers; D005983:Glutens; D007930:Leucine; D008239:Lysine; D009584:Nitrogen