A Thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, Resources and Developmen

Thesis (M.Sc.) - Asian Institute of Technology, 1993

Juvenile Sex reversed male Nile tilapia (Oreochromis niloticus) of average mean weight 33,6 g ± 5.6 (S.D) rere grown in fertilized pond conditions at stocking density of seven fish/ m using 18 different supplementary feeding strategies for 60 days. The study explored the possibility of achieving similar yields with varying protein offerings through mixed feeding schedules, compared to a situation of continuously high protein offering, The study comprised of two experiments. Experiment 1 accomplished mixed feeding schedules by using single diet of 33 % protein level, after alternating high feeding rate (2.3% body wt) and low feeding rate (1.5% body wt.). In Experiment 2, mixed feeding schedules were achieved after alternating 33 % protein level diet by 22 % diet. The rhythmic variation in Protein offerings in terms of days of high or low protein, were same in both experiments, Mixed feeding schedules resulted in similar yields compared to when fish was fed with continuous high feeding rate/ high protein diet, Significant improvement in feed utilization parameters such as apparent food conversion ratio, protein efficiency ratio and protein conversion efficiency was observed, The feed cost of producing one kg of fish, net return on feed cost were significantly improved. The mixed feeding schedule which was accomplished by two days of high feeding rate/ high protein diet followed by three days of low feeding rate/ low protein diet, performed the best. However, at present prices of inputs and outputs, mixed feeding schedules through single diet is shown to be economically more lucrative.