Growth performance, nutrient digestibility and lipase activity in juvenile rainbow trout (Oncorhynchus mykiss) fed fat powder in diet containing emulsifiers (cholic acid and Tween-80)

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. K E Y W O R D Semulsifier, enzyme activity, fat digestibility, fat powder, lipase, rainbow trout

Effects of bile acids on the growth performance, lipid metabolism, non‐specific immunity and intestinal microbiota of Pacific white shrimp ( Litopenaeus vannamei )

“…Similarly, our result showed that the addition of 0.2 g kg −1 bile acids in feeds could significantly enhance the growth performance together with the activities of lipase and protease of shrimp, indicating that bile acids may be also capable of promoting the emul- Dietary bile acids have been reported to affect serum biochemical indexes of juvenile rainbow trout (Adhami et al, 2017). TG is the most crucial ingredients of blood lipids, which can reflect the body's lipid metabolism status to some extent.…”

Effects of dietary visceral protein hydrolysate of rainbow trout on growth performance, carcass composition, digestibility and antioxidant enzyme in juvenileOncorhynchus mykiss

“…Emulsifying property is a characteristic of PHs which varies with factors like solubility and pH level as solubility increases with rising pH by which the emulsifying activity increases (Klompong et al, ; Mutilangi, Panyam, & Kilara, ). Emulsifiers mediate mixing of fats in water leading to the formation of polar and non‐polar molecules and facilitating the effect of lipase enzyme on these molecules and improving fat digestion (Adhami, Amirkolaie, Oraji, & Kenari, ). The deficiency of bile acids in the intestine decreases the digestion and absorption of fats, especially saturated fatty acids (Ketels, ).…”

Preliminary study to evaluate the effects of dietary bile acids on growth performance and lipid metabolism of juvenile genetically improved farmed tilapia (Oreochromis niloticus) fed plant ingredient-based diets

“…The gall bladder capsule of these fish was extremely fragile and easy to rupture. salts were found to improve the growth performance of rainbow trout (Adhami et al, 2017;Iwashita et al, 2008;Yamamoto et al, 2007) and turbot fed plant protein-based diets. Iwashita et al (2008) also reported that increased bile salt levels were observed in rainbow trout when cholytaurine (a bile acid) was supplemented to a plant-based diet.…”