| dc.description.abstract | In aquaculture fish undergo many operations from fry stage to adult stage that is Sampling, transportation, grading etc. these case a great deal of stress to the fish. However grading contributes the biggest percentage to the stress since it is carried out through out the production cycle. The study aims at investigating fish attraction using 2 plant scent extracts; Garlic and Onions and their effectiveness as alternatives to active grading of Nile tilapia and their potential impacts on the water quality Current grading techniques lead to over handling of fish that leads to stress responses such as death. 15 fish each in a tank across which a scent was applied using a sponge and separated by a grading grid. Attraction effects were measure by recording reaction time towards each scent. Each experiment was repeated 3 times and data collected was analyzed usingANOVA in R software and repeated measures ANOVA for pH. The results showed that there was a significant difference in reaction times between the scents (Garlic and onions) and control at P < 0.001 but no significant difference between the attraction effects of the scents that is Garlic and Onions at P = 0.145. This showed that grading with application of scents had better results. The repeated measures ANOVA test indicated that there was a significant difference in the pH before and after application of the scent at F = 1.989, df = 1 and p < 0.001 and a post Hoc test showed that there was a significant different in pH between Control and onion scent at p < 0.001, Control and Garlic at p < 0.001, garlic and Onion scents at p < 0.001 | en_US |
