Effect of Anise Essential Oil Supplementation on Growth Performance of Nile Tilapia Reared at Low Dissolved Oxygen Level

Medicinal herbs are the most utilized and validated feed additives in the aquaculture industry. This study investigated the dietary effects of anise (Pimpinella anisum L.) in Nile Tilapia (Oreochromis niloticus). Three sets of diets were prepared by spraying Anise essential oil on a commercial basal diet (30% crude protein) at the rate of 0 (control), 1, and 2 mL/kg diet. The experimental groups were assigned a 3 × 2 factorial design (3 level of anise oil; 0, 1, 2 ml) × 2 levels of dissolved oxygen (DO) concentration. The experiment was assembled as a control no anise (high DO), 1 ml + (high DO), 2 ml + (high DO), Control 0 ml (low DO), 1 ml anise (low DO), and 2 ml anise (low DO). Fish were fed the diets for 60 days consecutively at 3% body weight. The feed intake was recorded daily by subtracting the remaining feed in the containers from the total amount of feed before feeding. The results showed a marked enhancement in the growth performance and reduced feed conversion ratio in fish-fed anise compared to the control group. The carcass composition showed that crude protein was meaningfully by 2.5 and 3.5 g anise per kg diet. In conclusion, incorporating anise into the diet of Nile Tilapia is suggested to enhance performances and well-being.