Abstract
The 15N-isotope dilution technique (15N-IDT), with either pulse-dose oral administration or continuous i.v. administration of [15N]-L-leucine (carotid artery), both at 5 mg/(kg body weight · d), was used to measure ileal (postvalve T-cecum cannula) endogenous nitrogen recovery (ENR) in pigs (9 ± 0.6 kg). Diets were cornstarch, enzyme-hydrolyzed casein with no (control) or high (4%) content of quebracho extract (Schinopsis spp.) rich in condensed tannins. Blood was sampled from a catheter in the external jugular vein. Mean plasma 15N-enrichment at d 8-10 was higher (P = 0.0009) after i.v. than after oral administration [0.0356 vs. 0.0379 atom% excess (APE)]. Plasma 15N-enrichment for i.v. infused pigs was 0.01117 APE higher (P <0.0001) and for orally dosed pigs 0.0081 APE lower (P <0.0001) at 11 h postprandial compared with 1 h postprandial. Apparent ileal N digestibility was higher (P <0.0001) for the control (85.5%) than for the quebracho diet (69.5%). ENR was calculated from the ratio of 15N-enrichment of plasma and digesta. The ENR for the quebracho diet was 300% higher than for the control diet (6.03 vs. 1.94 g/kg dry matter intake, P <0.001). The real N digestibility (92.2 ± 0.4%) was equal for both diets (P = 0.1030) and both tracer methods (P = 0.9730). We concluded that oral administration of [15N]leucine provides reasonable estimates of ENR in pigs fed semipurified diets with high or low content of tannins; however, one must be careful in extrapolating this conclusion to studies with other protein sources or feeding frequencies
Original language | English |
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Pages (from-to) | 3068-3075 |
Journal | The Journal of Nutrition |
Volume | 134 |
Issue number | 11 |
DOIs | |
Publication status | Published - Nov 2004 |
Keywords
- amino-acid flows
- kg liveweight pig
- protein-free
- ileal digesta
- distal ileum
- growing pigs
- excretion
- infusion
- leucine
- losses