Open AccessGrowth performance, nutrient digestibility and lipase activity in juvenile rainbow trout ( Oncorhynchus mykiss ) fed fat powder in diet containing emulsifiers (cholic acid and Tween‐80)
Author(s) -
Adhami Batoul,
Amirkolaie Abdolsamad Keramat,
Oraji Hosein,
Kenari Reza Esmaeilzadeh
Publication year - 2017
Publication title -
aquaculture nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.941
H-Index - 79
eISSN - 1365-2095
pISSN - 1353-5773
DOI - 10.1111/anu.12484
Subject(s) - rainbow trout , lipase , biology , triglyceride , food science , cholic acid , nutrient , fish oil , juvenile , trout , zoology , cholesterol , biochemistry , fish <actinopterygii> , fishery , enzyme , ecology
Abstract This research was conducted to investigate the effects of two dietary emulsifiers on nutrient digestibility and lipase activity in rainbow trout ( Onchorhyncus mykiss ). A basal rainbow trout diet containing fat powder supplemented with 10 and 5 g kg −1 of cholic acid, and 20 and 40 g kg −1 of Tween‐80. Control diet contained no emulsifiers with fat powder was replaced by fish oil. Each diet was randomly assigned to 1,500‐L tanks in triplicate. Juvenile rainbow trout with an initial weight of 27.32 ± 2.03 g were randomly distributed in the experimental tanks. The results showed that growth parameters did not change by the addition of the two emulsifiers ( p > .05). Total triglyceride content was significantly higher in control fish fed diet containing fish oil ( p < .05), while serum cholesterol content showed no significant differences among treatments ( p > .05). Control diet resulted in a higher fat digestibility than those of other experimental diets. However, protein and ash digestibilities in diet containing emulsifier were higher than those of the control diet. Control group showed the lowest lipase activity, whereas 20 g kg −1 Tween‐80 diet caused the highest lipase activity among treatments ( p < .05). In conclusion, it seems that a higher lipase activity induced by the emulsifiers could not compensate for the negative impacts of fat powder on the experimental diets.