Effects of Feeds Containing Fermented Rice Bran and Sunflower Meal As Main Ingredients on Initial Growth and Body Composition of Tilapia Juveniles

Rice bran, a by-product of the rice milling process, is often discarded as a wasted resource despite its high nutritional value. This study focused on the fermentation process and mixing of rice bran with other agricultural wastes to make effective use of rice bran as fish feed, and aimed to clarify the effects of feeds prepared by adding sunflower meal and soybean meal to rice bran and fermented rice bran on growth and proximate composition. In the experiment, Japanese rice bran was fermented with Bacillus subtilis natto and lactic acid bacteria to produce Unfermented Rice bran Feed (URF) and Fermented Rice bran Feed (FRF), which were compared with Commercial Feed (COF). Fermentation increased the crude protein content of rice bran and decreased the crude fat content; the results of a 28-day rearing trial showed that both URF and FRF had lower weight gain and SGR and worse feed efficiency than COF. On the other hand, the proximate composition of tilapia fed fermented rice bran was similar to that of commercial compound feed, suggesting that fermented rice bran is a more suitable feed for tilapia than unfermented rice bran. These results suggest that fermented rice bran is a promising feed for tilapia. Future research should investigate the growth-promoting effects of optimising the fermentation conditions and combining it with other feed ingredients. Keywords Fermented rice bran; Nile tilapia; Sustainable aquaculture; Feed formulation; Growth response