EFFECTS OF ANIMAL-PLANT PROTEIN RATIO IN EXTRUDED AND EXPANDED FEED ON THE GROWTH PERFORMANCE OF JUVENILE CHINESE SOFT-SHELLED TURTLE (PELODISCUS SINENSIS WIEGMANN )

Effects of animal-plant protein ratio in extruded and expanded feed on feeding, growth rate, feed utilization and body composition of juvenile Chinese soft-shelled turtle (Pelodiscus sinensis ) were studied in this experiment. Four extruded and expanded feeds (dietsl-4) were formulated with different animal-plant protein ratios (diet 1,1.50： 1 ; diet 2,2.95: 1 ; diet 3,4.92: 1 and diet 4,7.29：1 ). Feeding rate of juvenile turtle fed diet 1 was significantly higher than those of the groups fed diet 2-4. There was no significant difference in specific growth rate among the groups fed diet 1-4. The apparent digestibility coefficients for dry mass and lipid of juvenile turtle fed diet 1 were both significantly lower than those of the groups fed diet 2-4. Feed conversion efficiency, protein retention efficiency and energy retention efficiency of juvenile turtle fed diet 1 were also significantly lower than those of the group fed diet 2-4. Body lipid content of juvenile turtle fed diet 1 was significantly lower than that of the group fed diet 4. There were no significant differences in the parameters described above among the groups of diet 2-4. Those results indicate that the growth performance of juvenile turtle is affected by the animal-plant protein ratio in extruded and expanded feed, and the optimum animal-plant protein ratio in extruded and expanded diets is around 3: 1.