Calculation of protein and energy requirements in beluga sturgeon (Huso huso) using a factorial approach

This study tried to determine the protein and energy requirements of growing beluga sturgeon Huso huso using a factorial approach. The experiment was composed of four small-scale growth trails covering different weight ranges. The fish fed at 0, 20, 40, 60, 80 and 100% of satiation. DWG had a steady increase throughout the experiment following a non-linear equation as Y = 1.433 (±0.056) × Ln(X) -2.740 (±0.261); r(2) = 0.99, p < 0.001, where Y = weight gain (g/day) and X = fish weight (g). The daily requirement of digestible energy (DE) for maintenance amounted to 79.09 kJ × BW (kg)(0.8) . The daily requirement of DP for maintenance calculated as 0.93 g × BW (kg)(0.7) . The relationship between DE intake (X) and DE gain (Y) expressed as Y = -0.0004 (±0.000) X(2) + 0.600 (±0.082) X -44.95 (± 6.72). Also, the relationship between DP intake (X) and protein gain (Y) was expressed as Y = -0.019 (±0.006) X(2) + 0.548 (±0.062) X - 0.498 (±0.121). The daily requirements of energy and protein were estimated as 79.09 kJ × BW (kg)(0.8) + 2.94 × DE gain and 0.93 g × BW (kg)(0.7) + 2.63 × DP gain. Apparently, beluga sturgeon is inefficient in converting energy and protein into body tissue. Therefore, energy content of the diet should be sufficiently high to satisfy large energy demands in beluga sturgeon and also to reduce the catabolism of protein.