EFFECTS OF DIETARY ENERGY - PROTEIN RATIO AND STOCKING DENSITY ON GROWTH AND SURVIVAL OF THE COMMON SNAPPING TURTLE CHELYDRA-SERPENTINA

Although the common snapping turtle Chelydra serpentina is cultured co mmercially in the United States, little information is available on nu tritional and culture requirements. This study was conducted to evalua te the effects of dietary energy:protein ratio and stocking density on survival, growth, feed consumption, feed conversion, liposomatic inde x, dress-out percentage, and productive protein value of cultured, com mon snapping turtles. Hatchling turtles were stocked at 29 and 58 anim als/m(2) and fed one of seven prepared diets. Six diets contained 30, 35, or 40% protein at two digestible energy (DE) levels (7 or 9 kcal D E/g protein); the seventh was a reference diet (66% protein and 5 kcal DE/g protein) formulated to equal or exceed the whole-body essential amino acid composition of wild, common snapping turtles. Turtles stock ed at 58/m(2) exhibited greater mortality, lower weight gain, higher f eed consumption, less-efficient feed conversion, lower liposomatic ind ex, and lower productive protein value than turtles stocked at 29/m(2) (P < 0.05). The reference diet produced the greatest weight gain (P < 0.001). The superior performance of turtles fed the reference diet su ggests that: 1) the protein (amino acid) content and/or energy:protein ratio of the reference diet was superior to that of the other diets t ested; 2) improvements in growth parameters can be made with dietary m anipulation; and 3) high levels of plant protein can be used in prepar ed, snapping turtle diets.