Effects of soybean and canola meals as dietary protein sources on the production performance and meat quality of shrimp

Abstract

Vegetable dietary protein sources are cheaper alternatives to fishmeal in shrimp diets. This study assessed the impact of fermented and non-fermented soybean and canola meals on growth performance, in vivo and in vitro digestibility, digestive enzyme activities and meat quality of Litopenaeus vannamei. A total of 513 shrimps were randomly assigned to treatments (control and two experimental diets). Animals on the control diet (cd) were fed a commercial feed concentrate. For the other treatments, the fishmeal protein source was totally replaced by a mixture of soybean and canola meal (50:50), either unfermented (sc) or fermented (fsc). Results showed that fermentation significantly increased (P < 0.05) the hydrolysis degree (hd) of sc meals by 12 % compared to that of their unfermented counterparts. Also, it was found that canola meal had higher hd compared to soybean meal, both before and after fermentation. The use of sc diet decreased protein digestibility in shrimps (P < 0.05), although there was no significant variation in the activity of total proteases and chymotrypsin. Production performance traits of shrimps fed diets with fsc were comparable to those of shrimps on the control diet. The increase in shear force of shrimps fed fsc was accompanied by an increase in the water holding capacity (whc) by 8-9 % (P < 0.05). Sensory attributes were similar across diets. In summary, this study showed it is possible to fully replace fish meal with fsc in shrimp diets without impairing production performance traits, dietary protein digestibility, and shrimp meat quality.