The effects of tannins on nutrient utilisation in the White Pekin duck

Citation
D. King et al., The effects of tannins on nutrient utilisation in the White Pekin duck, BR POULT SC, 41(5), 2000, pp. 630-639
Citations number
50
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Animal Sciences
Journal title
BRITISH POULTRY SCIENCE
ISSN journal
0007-1668 → ACNP
Volume
41
Issue
5
Year of publication
2000
Pages
630 - 639
Database
ISI
SICI code
0007-1668(200012)41:5<630:TEOTON>2.0.ZU;2-P
Abstract
1. Two experiments were conducted to determine the effects of tannins on nu trient utilisation in the White Pekin duck. 2. Experiment 1 was a rapid nutrient balance assay to determine the nitroge n (N) retention and metabolisable energy (ME) of maize, low-tannin sorghum (P-954063) (Sorghum bicolor (L). Moench) and high-tannin sorghum (IS-4225) cultivars for ducks. The assay lasted 120 h, with an initial 24 h food-depr ivation period, a 48 h excreta collection period for endogenous losses and a 48 h excreta collection period for ingredient losses. The true metabolisa ble energy (TMEn) content was lower (P < 0.05) in the high-tannin sorghum c ultivar (13.85 MJ/kg) than the maize (14.94 MJ/kg) and the low-tannin sorgh um cultivar (14.39 MJ/kg). True N retention was lower (P < 0.05) for the hi gh-tannin sorghum (0.24 g) than for maize (1.33 g) and low-tannin sorghum ( 1.31 g). 3. In experiment 2, the brush-border membrane vesicles technique was used t o determine whether tannic acid caused inhibition of L-threonine transport across duck intestinal brush-border membrane. The brush-border membrane ves icles were mixed with tannic acid solutions (pH 7.4) to give gradient tanni c acid concentrations of 0, 0.05, 0.10, 0.25, 0.50, 1.00 and 2.50%. As a fr action of the control (no tannic acid), the maximal inhibition of L-threoni ne transport (I-max) under the sodium-gradient condition was 77.10% (P < 0. 05). Under the sodium-free condition, the maximal inhibition of L-threonine transport (I-max) was 45.15% (P < 0.05). 4. These results demonstrated that nutrient utilisation in the White Pekin duck was lower from the high-tannin sorghum cultivar than from the low-tann in sorghum cultivar. The results also suggested that the antinutritive effe cts of tannins in foodstuffs are due partly to their inhibitory action on i ntestinal brush-border bound amino acid transporter proteins.