Digestibility, feeding and growth studies were conducted with Nile tilapia using diets containing ¢shery by-catch and processing waste meals. Three meals manufactured from sorted ¢sheries by-catch (MBM, from mixed benthic species, SPM, from small pelagic species, CAM, from mixed cat¢sh species) one from tuna cannery waste (TCW) and one commercial anchovy meal (COM) were tested. By-catch and processing waste meals had lower protein, lower lipid and higher ash contents than anchovy meal. The meals were all highly digestible and no signi¢cant di¡erences (P ! 0.05) were observed between apparent protein digestibility measurements. Five feeds, containing ¢sh meal as the major protein ingredient, were formulated and fed to triplicate groups of 30 juvenile tilapias for 9 weeks. Survival, weight gain, spe-ci¢c growth rate (SGR), feed conversion ratio, protein e⁄ciency ratio, phosphorus retention and whole body proximate composition were compared. Weight gain and SGRs were similar for each treatment group and compared favourably with the results obtained from juvenile tilapia elsewhere. Growth was the highest for CAM (P 0.05), which contained both the highest essential amino acid levels and the highest ash content. Phosphorus retention was signi¢cantly lower in ¢sh fed with high ash meals, MBM, CAM and TCW (P 0.05) than in ¢sh fed with the lower ash meals COM and SPM. Overall, the ¢sheries by-catch and processing waste meals evaluated in this study are suitable protein ingredients for juvenile tilapia feeds.Ã Values are mean (standard deviation) of triplicate measurements.Aquaculture Research, 2008, 39, 518^525 Fisheries by-catch meals in tilapia diets S Goddard et al.

No abstract