Nile tilapia (Oreochromis niloticus) is one of the most aquacultured fish species worldwide, mainly due to its rapid growth performance and market value. However, as occurs for other farmed species, its growth performance, feed efficiency and disease resistance are usually challenged by stressful situations derived from common culture practices. Phytogenic feed additives (PFA) have been demonstrated to be potential tools to improve production performance.
The present study was conducted to determine the efficacy of a new phytogenic feed additive (PFA) mixture (saponins, spices and essential oils) on Nile tilapia juveniles growth performance and feed efficiency. Two isoenergetic and isoproteic diets were formulated to contain different levels of PFA bioactives (control diet: 0 ppm, PFA diet: 30 ppm) and fed for 8 weeks to Nile tilapia juveniles (initial weight: 13.05±0.27g). The trial was conducted in a 350 L tanks outfitted with a biological filter and an aeration system, with 3 replicates by diet. Water temperature was kept at 27.9±0.6ºC, dissolved oxygen and pH were monitored daily whereas total ammonia and nitrite were measured 2 times a week. At the end of the feeding trial, feces and tissue samples were collected for nutrient digestibility and digestive enzyme activities analyses.
After 8 weeks of dietary PFA supplementation, fish fed the PFA diet presented improved weight gain and showed improved (p<0.01) specific growth rate (SGR) and higher (p<0.01) feed intake (Figure 1). Results obtained are related to the nutrient digestibility and digestive enzyme activities findings. Altogether indicating that the use of the PFA blend tested can promote growth performance of Nile tilapia juveniles.