Effect of different protein contents mix feed composition on growth performance, feed conversation and body composition in European Catfish (Silurus glanis L., 1758) fry

In this study, it was aimed to determine the optimum protein ratio required in the feed ration of European catfish (Silurus glanis) fry with two different weights (5 g and 100 g). Based on this, in the two-stage study, control (45/15), 35/8, 40/8, 45/8 and 50/8 feeds with protein/lipid ratio were prepared for fry weighing 5 g, control (45/15), 30/8, 35/8, 40/8 and 45/8 feeds with protein/lipid ratio were prepared for fry weighing 100 g. For each stage, the pups were fed these feds for 90 days. Physico chemical, biometric, morphometric, digestibility and feed analyzes of the data and samples obtained from the field work of the thesis, which lasted for a total of 411 days, were subjected to statistical evaluation. Based on the biometric data, the best values were obtained in the control (45/15) group, which had a higher energy level compared to the other groups, while the best values for both fry weights were obtained from the 40/8 group with 40% protein. As a result of the broken line regression analysis using the specific growth rate data, it is recommended that the optimum protein level in the feed ration is 40.68% for 5 g fry and 39.98% for 100 g fry. While the results obtained overlap with the literature studies, a more detailed result was revealed in the determination of the optimum protein ratio required in the feed ration of European catfish fry with many analyzes made in the thesis study. With this thesis, it is aimed to contribute to the production of commercial feed specific to European catfish, and thus to support the spread of European catfish in our country.