Effects of protease supplementation in low fish meal pelleted and extruded diets on growth, nutrient retention and digestibility of gibel carp, Carassius auratus gibelio

Organic acid salts, protease and their combination in fish meal‐free diets improved growth, nutrient retention and digestibility of tilapia ( Oreochromis niloticus × O. aureus )

“…The improved growth and digestibility by the supplemental protease might come from the hydrolysis of protein, the degradation of dietary antinutritional factors (Caine & Verstegen, 1998) and the improvement of intestinal structure (Wu, 2007;Zhang et al, 2012). In this study, dietary protease did not significantly improved the growth and nutrient digestibility (Tables 2 and 5), while in previous studies, this protease complex did Shi et al, 2016). The reasons may exist in the fish meal substitution level and the protein source substituting fish meal.…”

“…The studies in fishes showed that dietary protease significantly increased protease activities in stomach and intestine (Song, ; Zhang, Li, Leng, Han, & Zhang, ), enhanced nutrient digestibility (Chen et al., ; Drew, Racz, Gauthier, & Thiessen, ) and improved the histological structure of digestive tract (Wu, ; Zhang et al., ). The positive effects of exogenous protease on growth performance were also reported in rainbow trout (Zhang et al., ), black carp ( Mylopharyngodon piceus ) (Chen et al., ), crucian carp (Shi, Li, Chowdhury, Chen, & Leng, ), tilapia ( Oreochromis niloticus × O. Aureus) (Li, Chai, Liu, Chowdhury, & Leng, ) and Pacific white shrimp (Li et al., ; Song et al., ).…”

“…In previous studies, the dietary supplementation of protease in low fish meal diets improved the growth performance of gibel carp (Shi et al., ), tilapia and Pacific white shrimp (Li et al., ). Similar results were also reported in black carp (Chen et al., ), Atlantic salmon ( Salmo salar ) (Carter, Houlihan, Buchanan, & Mitchell, ) and tilapia (Lin, Mai, & Tan, ) .…”

Effects of dietary coated protease on growth performance, feed utilization, nutrient apparent digestibility, intestinal and hepatopancreas structure in juvenile Gibel carp (Carassius auratus gibelio )

“…And Shi et al. () reported that adding protease in low fishmeal pelleted diet, but not to the extruded diet, improved the growth and nutrient utilization of large Carassius auratus gibelio (35.0 ± 0.2 g), but the dietary protease on physiology and biochemistry of Carassius auratus gibelio was not involved. Nevertheless, Peek, Van der Klis, Vermeulenc, and Landmana () reported that the adherent mucus layer of the duodenum, jejunum and caeca was significantly thicker in broiler chickens fed the protease‐supplemented diet.…”

Exogenous enzymes as functional additives in finfish aquaculture

“…Similar trend was also determined in the process of exogenous protease added into coextruded canola:pea‐based diets, resulted in an significant increment of feed efficiency and better nutrient utilization in rainbow trout (Drew et al, ). Furthermore, Shi et al () stated that the supplementation of 150 and 175 mg/kg protease diet significantly improved weight gain, nutrient apparent digestibility coefficients, nutrient retention and decreased feed conversion ratio (FCR) in pelleted diets, when compared to negative control ( p < .05), while no significant differences in growth, nutrient digestibility and retention were observed among treatments in extruded diets. It also showed that the addition of protease to the canola:pea diet resulted in a significant improvement in feed efficiency, while the supplementation of protease to flax:pea product in trout had no effect on nutrient digestibility (Drew et al, ).…”