Effect of Ration Level on Growth in Juvenile Softshelled Turtles,Trionyx sinensis

The growth trial of a 56-day period was conducted at 30 ℃ to investigate the effect of ration on growth and feed conversion efficiency in juveniles Trionyx sinensis,which initial body weights ranged from 28.66 to 53.37 g.They were fed commercial soft-shelled turtle diet twice a day at five ration levels (starvation,1%,2%,4% and satiation).ANOVA showed that specific growth rate (SGR) and conversion efficiency (K) were significantly affected by the ration level.SGR increased quadratically with increasing ration,and the relationship between SGR for dry matter (SGRd) and ration level (RL) could be expressed as the follow:SGRd=-0.0832RL2+1.0795RL-1.8779(n=25,r2=0.906,F=105.46).The maximum SGR for wet matter,dry matter,protein and energy appeared when ration levels were 6.97%,6.49%,6.08% and 6.34%,respectively.All Ks at 1% ration group were significantly lower than those at 2% and 4%,and Ks for dry matter and energy were lower than the satiation;Ks for dry matter and energy at 2% were significantly higher than those at the satiation.