|Maintenance threonine requirement and efficiency of its use for accretion of whole-body threonine and protein in Atlantic salmon (Salmo salar L.) fry|Rollin, X.; Wauters, J.-B.; Bodin, N.; Larondelle, Y.; Ooghe, W.; Wathelet, B.; Abboudi, T. (2006). Maintenance threonine requirement and efficiency of its use for accretion of whole-body threonine and protein in Atlantic salmon (Salmo salar L.) fry. Br. j. nutr. 95(2): 234-245. dx.doi.org/10.1079/BJN20051491
In: British Journal of Nutrition. Cambridge University Press: London. ISSN 0007-1145, more
threonine; amino acids; Atlantic salmon fry; maintenance requirement;growth requirement
|Authors|| || Top |
- Ooghe, W., more
- Wathelet, B.
- Abboudi, T., more
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°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/16g N basis) as in the Atlantic salmon fry whole-body carcass. Following 36d of feeding and a 36h 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 5·4mg Thr/kg body weight0·75 per d. The Thr maintenance requirement was 7·2mg/kg body weight0·75 per d and the Thr requirement for growth was 66mg for 1g 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.