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

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

Thesis (M. Sc.) - Asian Institute of Technology, 2000

This study was undertaken to evaluate the partial or total replacement of fish meal with soybean meal in diets on growth response of Jambal Siam catfish (Pangasius hypophthalmus). The experiment was conducted in cages (1 xl x 1.2 m) installed in the earthen ponds at stocking density of 10 fish per cage. Six isonitrogenous experimental diets were formulated to contain 0, 5, 10, 15, 20, and 50% fish meal and 65, 58, 53, 46, 40, and 0% soybean meal (TA, TB, TC, TD, TE, and TF, respectively). Diets were fed to experimental fish twice daily at a feeding allowance of 5% body weight per day for 56 days. The results indicated that a diet containing 32% crude protein with 20% fish meal and 40% soybean meal (TE) support a good growth rate (specific growth rate: 3.55 %/day, daily weight gain: 1.52 g/day, survival rate: 100%) and efficient feed utilization (food conversion ratio: 1.22) comparable to fish fed diet containing 50% fish meal (TF/control). Partial replacement of fish meal with soybean meal was acceptable in formulated diets for Jambal Siam catfish, while complete replacement of fish meal resulted a low growth rate of this experimental fish. In the present study indicated that Pangasius hypophthalmus require about 15 to 20% fish meal in diet containing 32% crude protein for optimal growth