This study was aimed at evaluating the growth of grass carp juveniles (Ctenopharyngodon idella) fed with teosinte grass (Euchlaena mexicana) and supplied with different feeding rates. Two experiments were done (45 days each), using 240 juveniles (weight=10.33 ± 0.33 and 20.15 ± 0.23g). In the first, four feeding rates (1, 2, 3 and 4% of body weight (BW), called S1, S2, S3 and S4 respectively) were tested. In the second, the treatments were: C = Only teosinte grass; SD = Teosinte grass + ration daily (3%BW); SA = Teosinte grass + ration each 2 days (3%BW); R = Only ration (3%BW). In the experiment 1, it was observed a weight increasing following the ration supply. The higher specific growth rate was obtained in S4. No differences among treatments was verify for carcass yield, however, the fillet yield was higher in S3 and S4. In the experiment 2, weight was higher in SD. The carcass yield (RC) did not present significant difference among the treatments in the experiment 2. Fillet yield was lower in fish fed only with teosinte grass (C). We concluded that the grass carp juveniles growing is positively affected by association of teosinte grass and ration supply, being necessary a minimum feeding rate (3%BW) daily for achieving good growth.
nutrition; forage; fish; ration; carcass yield