Effects of three positively buoyant dietary supplements on the buoyancy of feces, growth and intestinal health of Tilapia, Oreochromis niloticus×O. aureus

摘要

Two trials were conducted to evaluate the effects of positively buoyant dietary materials on growth, intestinal health, and fecal properties of tilapia. In trial 1, ten diets containing 0 (control) 1%, 2% or 3% cork, expanded and vitrified microball or expanded vermiculilite fine particles (250–450?μm) were fed to tilapia fry (5.0?±?0.1?g) for 30 days to evaluate the effects on the growth and feeding efficiencies. In trial 2, the three buoyant materials with coarse particles (450–830?μm) were included in diets at 0 (control), 3%, 4% or 5% supplementation levels to feed tilapia juveniles (55.0?±?1.0?g), and the growth, feed efficiencies, evacuation velocity, fecal floatability and intestinal histology were examined after 21 days feeding. In trial 1, the weight gain (WG) of the fish significantly decreased with the supplementation of 2%, 3% cork, 3% microball or 3% vermiculite (P?