Protein lipid ratio for the growth and survival of juvenile crayfish Procambarus acanthophorus (Hobbs 1972) reared under controlled conditions

摘要

The influence of dietary protein/lipid levels on growth and survival in juvenile crayfish (Procambarus acanthophorus) was evaluated during a 12-week nutritional trial. Twenty experimental diets were formulated containing different protein (200, 250, 300, 350 and 400 g kgp#) and lipid (60, 80, 100 and 120 g kgp#) levels. A bifactorial model (5 x 4) was used with three replicates and 15 crayfish (0.014pl0.006 g) per replicate, in a recirculation system with 60-15 L rectangular tanks and a biological filter, the culture conditions were a photoperiod of 12:12 h L:D and temperature 24.7pl1.0 pC. Total survival ranged from 66.6% to 86.6%, with no differences attributed to treatments. Dietary protein levels had a significant effect on growth gain and nutritional efficiency; in contrast, lipid levels had no effect on juvenile performance. The 250/120 (protein/lipid) treatment promoted the most efficient growth (final weight: 3.09 g, weight gain: 21 995%, specific growth rate: 3.35% dayp#); the less efficient growth was observed in juveniles fed with 400 g kgp# protein diets. The quadratic regression model indicated 279 g kgp# as the optimal protein level for crayfish growth, while levels between 211 and 232 g kgp# could minimize the feeding costs without affecting growth.