Effect of three feeding management systems on some reproductive parameters of Scorpion mud turtles (Kinosternon scorpioides) in Brazil

Abstract

Chelonians have been exploited since ancient times for their meat, eggs, fat, and offal, among other things. Among these animals, there is Scorpion mud turtle (Kinosternon scorpioides) which is an omnivorous turtle with semiaquatic habits and is widely consumed in Brazil. The aim of this study was to evaluate the influence of different feeding management systems on the reproductive performance of captive-bred Scorpion mud turtles, including egg quality and chemical composition. Study animals included 15 males and 48 females, divided into three groups. Animals were fed with either a commercial diet or a commercial diet supplemented with one of two different mixes (wet diet). All animals were fed at 1% BW/day divided on Mondays, Wednesdays, and Fridays. Treatments were as follows: TR = 100% fish food (22% CP); TRM1 = 70% fish food + 30% mix 1 (bovine offal and fish); TRM2 = 70% fish food + 30% mix 2 (bovine offal, fish, and shrimp). Samples were collected during 7months, and eggs were identified, weighed, measured, and frozen for later analysis. Statistical analyses, including ANOVA, were performed using the program SAEG 9.0. Measurements taken from the nests were compared using the Tukey's test (P < 0.05). The different diets were associated with differential egg-laying performance and eggshell thickness. Animals fed with wet diets containing protein of animal origin displayed the best performance. Furthermore, nests with fewer eggs contained eggs of better external quality (e.g., greater length, width, and eggshell thickness). Finally, animals fed with only commercial feed produced eggs with lower saturated fatty acid content.