| Autor: |
Rollin X; Laboratoire de Pisciculture M. Huet, Université catholique de Louvain, Route de Blocry, 2, B-1348 Louvain-la-Neuve, Belgium. rollin@efor.ucl.ac.be, Wauters JB, Bodin NL, Larondelle Y, Ooghe W, Wathelet B, Abboudi T |
| Jazyk: |
angličtina |
| Zdroj: |
The British journal of nutrition [Br J Nutr] 2006 Feb; Vol. 95 (2), pp. 234-45. |
| DOI: |
10.1079/bjn20051491 |
| Abstrakt: |
Eighteen groups of seventy Atlantic salmon (Salmo salar L.) fry (initial mean body weight 0.8 (sd 0.01) g) were fed on semi-purified diets containing graded levels of l-threonine (Thr) in 15 litres aquaria at a temperature of 14.5+/-1 degrees C. Doses of Thr represented 1, 31, 41, 51, 62, 72, 83 and 93 % of its ideal level for optimum protein deposition. Indispensable amino acids other than Thr were included in the same proportion (on a g/16 g N basis) as in the Atlantic salmon fry whole-body carcass. Following 36 d of feeding and a 36 h fast, fry were killed for whole-body protein and amino acid analysis. Weight gain (r2 0.98), protein accretion (r2 0.97), and Thr accretion (r2 0.97) were linear (P<0.01) functions of Thr intake. Slope of the Thr accretion regression line showed that the efficiency of Thr utilisation above maintenance was 76 %. At zero Thr intake, fry lost 5.4 mg Thr/kg body weight0.75 per d. The Thr maintenance requirement was 7.2 mg/kg body weight0.75 per d and the Thr requirement for growth was 66 mg for 1 g protein deposition. Increasing doses of Thr resulted in increased (P<0.05) concentrations of histidine and lysine, and decreased concentrations of isoleucine in whole-body protein. The maintenance need for Thr represented 13.4 % of the total need for Thr. The data suggest that efficiency of Thr utilisation above maintenance is constant at all levels of Thr intake between 1 and 93 % of the level required for optimum protein deposition. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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