EVALUATION OF CASSAVA CHIPS AS AN ALTERNATIVE FEED INGREDIENT IN TILAPIA Oreochromis niloticus AQUACULTURE FROM A GUT HEALTH PERSPECTIVE

In order to increase aquaculture production while reducing production costs, alternative ingredients must be investigated to reduce the dependency on conventional energy sources in aquaculture feeds. Modulation of the intestinal microbiota of aquaculture species through the use of prebiotics not only benefits the health of the host, but also reduces costs to aquaculture production. Like prebiotics, feed ingredients with high fiber and resistant starch also modulate the intestinal microbiota of the host while providing nutritional value for growth performance. Tilapia (Oreochromis sp.) are the most widespread aquaculture species in the world due to their relative fecundity, omnivorous feeding habits, and tolerance of marginal growing conditions, making them ideal study species for alternative feed ingredients. This study investigated the use of sun-dried cassava (Manihot esculenta) chips as corn replacement to reduce feed cost while maintaining production levels of tilapia (O. niloticus × O. mossambicus). Four hundred tilapia fingerlings (~10g initial body weight) were randomly and equally placed in 20 tanks and fed with one of the 5 diets with 0, 4.38, 8.75, 17.5, and 26.25% cassava inclusion in basal diets for 12 weeks. Feed intake and body weight was recorded weekly and intestinal and environmental samples were collected monthly and processed for microbiota analysis using PCR-DGGE, metagenomics and qPCR. Tilapia growth performance was not significantly different among treatments (P>0.05), suggesting that cassava can be incorporated up to 26.25% into the tilapia diets without negative impact. Additionally, cassava inclusion into the tilapia diets significantly altered the intestinal microbiota, which can be used as a strategy to modulate gut health of Tilapia.