Effects of short-term adaptation of weaning strategies on growth performance, survival rate, carcass composition, and fatty acids profile of great sturgeon (Huso huso) larvae

This study aimed to evaluate the effects of feeding with different types of live feeds on growth performance, survival rate, body composition, and fatty acids profile of great sturgeon (Huso huso) larvae during short-time weaning to dry feed. A total of 1200 great sturgeon larvae with a mean initial weight of 0.43±0.01g were distributed randomly into twelve 80-L circular fiberglass tanks (100 larvae per tank) with three replicates. Afterward, the fish were fed with frozen chironomid larvae (T1), frozen Artemia biomass (T2), and a combination of them (T3). The control group © received only a commercial dry feed (0.5 mm: protein 55.59%, lipid 21.12%, ash 11.76%, and moisture 7.96%) throughout the feeding trial. For weaning, the live feed was reduced by 15% every two days, and the dry feed ratio was also gradually increased. According to the results, the final weight (4.99±0.16g), weight gain (4.57±0.17g), body weight increase (1081.53±72.75%), and specific growth rate (11.75±0.29%/day) were significantly higher in T1 than in other groups (p<0.05). The survival rate (56.50±1.32%) significantly decreased in the control group © (p<0.05); however, no mortality was observed in the group fed chironomid larvae (p<0.05). The crude lipid (1.32±0.08%) and moisture (80.98±0.17%) levels of T1 were higher than other groups, and the crude protein content was significantly higher in T3 (11.26±0.39%) and C (11.44±0.44%) than T1 (9.23±0.39%) and T2 (9.67±0.28%) groups (p<0.05). There was a significant decrease in total n-3 LC-PUFA fatty acids (9.53±0.04%) in T3 than in T1 (11.02±071%) (p<0.05). The EPA/DHA ratio in T1 was significantly higher (0.45±0.03%) than other treatments (p<0.05). Consequently, the administration of frozen chironomid larvae is recommended during a 21-day adaptation period of great sturgeon larvae to the dry feed, due to the optimizing effects on growth indices, survival, and fatty acid contents.