Use of canola meal in the diet of grasscarp fry (<em>Ctenopharyngodon idella</em> V.)

Abstract

One hundred fry with 1.33 mean weight and 5.06cm mean length distributed in twenty 50-liter aquarium, with 5 fish each, were used in a completely randomized plotted experiment, with 4 replications, to evaluate the effects of soybean meal (SM) protein replacement by canola meal (CM) protein in diets for grasscarp fry (Ctenopharyngodon idella V.). Five substitution levels of SM protein by CM protein (0.00%, 20.00%, 40.00%, 60.00% and 80.00%) corresponding to 0.00%, 8.04%, 16.10%, 24.10% and 32.15% diet-included CM were used. Isoproteinic, isocalcic and isophosphoric meals were given during 28 days, while physical and chemical parameters were monitored. The results of the investigation as for performance characteristics revealed that weight gain, relative growth rate, protein efficiency rate, feed conversion, survival rate and cost of diet/kg weight gain were not affected, while final weight (Y=2.39190 + 0.01327X - 0.00019X², r² = 0.78), total length (Y= 6.15270 + 0.01195 X - 0.00016X², r² = 0.86) and total length increase (Y= 1.10340 + 0.01198 X - 0.00016X², r² = 0.86) suffered quadratic effects. Physical and chemical parameters remained within appropriate level range. The substitution level of 35.79% SM protein by CM protein or diet inclusion CM of 14.40% presented the best performance for grasscarp fry.