Maintenance threonine requirement and efficiency of its use for accretion of whole-body threonine and protein in Atlantic salmon (Salmo salar L.) fry

Abstract

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 14·5^18C. 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 (r 2 0·98), protein accretion (r 2 0·97), and Thr accretion (r 2 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 weight 0·75 per d. The Thr maintenance requirement was 7·2 mg/kg body weight 0·75 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.

Effect of dietary arginine on growth, intestinal enzyme activities and gene expression in muscle, hepatopancreas and intestine of juvenile Jian carp (Cyprinus carpiovar. Jian)

“…The reduction in weight gain with arginine levels above the requirement level might be due to (1) extra energy expenditure for deamination; (2) disturbance of absorption and utilisation of other amino acids; (3) lower palatability of the diet; or (4) toxic effects and stress ( 81 ) . A reduction of FI was regarded as the primary factor responsible for the depressed growth observed in Atlantic salmon fry ( 82 ) and European sea bass ( 83 ) . The arginine requirement estimated from SGR by using a quadratic regression analysis was 18·0 g/kg diet, which corresponded to 55·0 g/kg of dietary protein (Fig.…”

The Potential of Whole Soya Bean Meal in Raising Nile Tilapia (Oreochromis Niloticus, L.) Fingerlings

“…Bodin et al (2009) obtained a markedly higher estimate of maintenance lysine requirement (24 mg/kg 0.75 /day) for rainbow trout. Abboudi et al (2006); Rollin et al (2006) estimated the threonine maintenance requirement of Atlantic salmon fry (live weight = 1˗2 g/fish) to be between 5˗7 mg/kg 0.75 /day. NRC (2011) reported that the ideal amino acid patterns are usually stated as the ratio of each EAA to lysine, which is given the arbitrary value of 100.…”