Effect of protein restriction with subsequent re-alimentation on compensatory growth of juvenile soft-shelled turtles (Pelodiscus sinensis)

Abstract

The effects of protein restriction with subsequent re-alimentation on compensatory growth (CG) of juvenile soft-shelled turtles (Pelodiscus sinensis) were investigated. The turtles were fed five diets containing different crude protein content (T1: 29.24%, T2: 31.42%, T3: 34.19%, T4: 37.16%, C: 43.31%), while the energy content remained constant for 4 weeks (restriction period) and then re-fed a diet (43.31% crude protein) for 7 weeks (re-alimentation period). During the restriction period, feed conversion ratio (FCR) significantly increased in all protein-restricted groups (T1–T4) compared with the control group (C). At the end of the restriction period, body mass in groups T1 and T2 was significantly lower than that in the control group. During the re-alimentation phase, weekly body mass gain in group T1 was greater than that of the control from week 5 to week 10. FCR significantly decreased in group T1 compared with the control. No significant differences in final body mass between C and T1 groups were found at the end of the re-alimentation period. These results indicated that soft-shelled turtles receiving a diet in which protein was reduced from 43.31 to 29.24% (approximate 33% reduction) for 4 weeks achieved a 6 week complete CG response.