Wutiporn Phromkunthong and Anchalee Pipattanawattanakul

pp. 115 - 132

Abstract

A 8-wk feeding trial was carried out for hybrid catfish with an initial average weight of 7 g in 235-l
glass tanks attached to closed-recirculating system with 0.8 l/min flow rate. Feeds containing varying
percentages of dry Spirulina sp. 0, 5, 10, 15, 20, 25 and 30% were tested with three replications for each
treatment. All the feeds were formulated to contain dietary requirement for the catfish i.e. 30% protein, 7%
fat and 360 kcal gross energy/ 100 g feed. The results showed that the feed with 10% Spirulina sp. achieved
the best performance on weight gain, specific growth rate, feed conversion ratio, apparent net protein utilization and development of antibody levels against bacteria Aeromonas hydrophila. The total carotenoid contents in fish flesh increased with the level of Spirulina sp. supplemented. The supplementation of
Spirulina sp. resulted in no changes of blood parameters or histology.