| Summary: | 碩士 === 國立臺灣海洋大學 === 水產養殖學系 === 98 === Abstract
A 12 week feeding trial was conducted on hybrid tilapia (Oreochromis niloticus x Oreochromis aureus) fingerlings of 11.5-15.5g at a stocking density of 12 fish per aquarium and fed twice daily (9 am and 7 pm) for 12 weeks. The purpose of this study was to find out the effects of dietary protein, lipid and feeding levels, on growth, blood and biological parameters. Four experimental diets of similar energy levels were prepared. Two of the diets contain 30% crude protein with either 12% or 6% lipid level while the other two contain 20% crude protein with either 12% or 6% lipid level. Each diet was administered in three different feeding ways (100, 80, and 60%) except the diet with low dietary protein and lipid which was administered in two feeding way (100 and 80%. At the end of 8 weeks, the effects of dietary protein, lipid and feeding levels on final body weight, percent weight gain, specific growth rate, feed efficiency, feed intake, plasma triglyceride, cholesterol, glucose and total protein were measured. At the end of 12 weeks, in addition to growth and blood parameters, biological parameters such as hepatosomatic index, viscerosomatic index, intraperitoneal fat, condition factor and intestinal length ratio were also measured.
Dietary protein level has positive effects on percent weight gain, specific growth rate, feed efficiency, hepatosomatic index and intraperitoneal fat but negative effects on plasma triglyceride, cholesterol and total protein both at the end of 8 and 12 weeks. Dietary lipid level has negative effects on percent weight gain, specific growth rate and feed intake but positive effects on plasma glucose, viscerosomatic index and intraperitoneal fat. Feeding level has positive influences on percent weight gain, specific growth rate, feed intake, total protein, plasma glucose, hepatosomatic index, viscerosomatic index and intraperitoneal fat.
The best growth performances were observed in fish fed with high protein with low lipid diet. It may be concluded that sub-satiation feeding would be more beneficial than satiation feeding. My results suggest the range of crude protein between 20 and 30%, crude lipid 6% in diet, and feeding rates between 80 and 100% for best rearing performances.
Key words: hybrid tilapia (Oreochromis niloticus x Oreochromis aureus), protein level, lipid level, feeding rate, growth performance.
|
|---|
