Phytobiotic enhances growth, gut health and immunity of GIFT challenged with consortium of bacteria.

Abstract

The culture of genetically improved farm tilapia (GIFT) has been successfully introduced in Nigeria. Study on the growth and immune responses of this fish to local feeds is important. Moreover, the use of imported feed and growth promoters is not cost effective prompting search for alternatives. This study evaluated how phytogenic feed can possibly enhance growth and immune responses of this fish. Six novel aqua-feed were produced using oyster mushroom (MU) and turmeric (TU) in the following ratio (MU:TU): Feed 1, 148:0g, Feed 2, 104:44g, Feed 3 84:64g, Feed 4 , 64:84g, Feed 5 44:104g and Feed 6 60:148g respectively. GIFT tilapia of average weight 2.4g, were stocked at 10 fish per three replicate treatment feed aquaria, and fed for 60 days. After the feeding experiment 4 fishes were selected from the replicates and left for further 10 days before being challenged with consortia of bacteria. The fish treated with Feed 3 had the best specific growth rate (SGR) of 2.43±0.22% day-1, the best food conversion ratio (FCR) of 0.87±0.09 and the highest final weight of 103.00±0.08g. The best protein conversion and efficiency ratios and survival rates were also recorded in this treatment group. The group treated with Feed 1 was next to Feed 3 in performances. Those on Feed 6 had the lowest final weight 84g. Gut histological analysis showed photomicrograph of broad healthy mucosal fold size villi of about 300µm in length, and 70 µm in width, with densely populated enteroendocrine cells, paneth cells, and goblet cell. The best survival rates were recorded in fish treated with lower turmeric inclusions in feed. The results showed that Feed 3 could be adopted in the production of GIFT tilapia in terms of growth and inert immunity.