Biological attribute and disease resistance of catfish Clarias gariepinus (Burchell 1822) supplemented with different rations of spirulina Arthrospira platensis

Spirulina Arthrospira platensis is practically used as a supplement in nutrition due to its high nutritional content. Improving the feed formulation by combining the commercial fish feed with spirulina to the cultured fish might elevate the fish growth performance, nutritional value and increase its resistance towards bacterial infection. This study was conducted to determine the growth performance, nutritional value and disease resistance of catfish Clarias gariepinus (Burchell 1822) supplemented with different ration of spirulina, A. platensis. Five experimental diets were prepared by varying the percentage of spirulina in the fish feed containing 0% (control), 1%, 3%, 5% and 7% respectively of locally grown spirulina. A total of 30 fry (2.62±0.04gof fish initial total body weight; 7.09±0.05 cm of total body length) were stocked per cage and in triplicate. Each diet was fed to the fry twice daily at 5% of fish body weight for 90 consecutive days. Growth performances were determined every fortnight. The proximate analysis of spirulina, experimental diets and catfish fillet was done according to the method of AOAC, 1990. The catfish were then intraperitoneally injected with 107 CFU/ml of virulent Aeromonas hydrophila on day 91, and monitored until day 104. Catfish with diet of 7% spirulina produced significantly higher (p0.05) between all the diet groups. The feed conversion rate marginally decreased as spirulina inclusion increased in the diet, but not significantly different (p>0.05) between all the treatment groups. The gonado somatic index value was the highest in catfish with diet 7% spirulina but not significantly different (p>0.05) between all the treatment groups. The hepatosomatic index and viscerosomatic index value were also not significantly different (p>0.05) between all the treatment groups. The proximate compositions of the locally grown dried spirulina showed the highest content was the crude protein with 63.07±0.02% (p0.05) different between all the experimental diet groups. The content of proximate composition of catfish fillet showed at par to the control group with no significant different (p>0.05) between all diet groups except the crude fiber content that were significantly increased (p0.05) at 5% and 7% of spirulina diet. The percentage of catfish survive following A. hydrophila infection were significantly low (p<0.05) in control with 36.67% but not with other treatment groups range from 70.00% to 73.33%. The white blood cell count value was significantly higher (p