Aquafeed is a crucial indicator of success in aquaculture, especially for commercial aquaculture. This is because the cost of feeding accounts for more than 70% of the total production costs in each production cycle. Currently, challenges in commercial aquaculture and efforts to address these issues include the selection of additives to promote growth and improve feed efficiency as a means to reduce feed costs. Saponins are natural compounds found in various plants. They have a glycoside structure, saponins extracted from soapbark tree (Quillaja saponaria) and Mojave yucca (Yucca schidigera) have proven to be very promising ingredients for aquafeeds as natural growth promoters in aquatic animals.
The current work was designed to investigate the dietary effects of saponin on tilapia (Oreochromis niloticus). Fish with initial average weight 34.99±1.00 g/fish were randomly divided into five treatments in four replicates. Four experimental diets were designed containing different inclusion of saponin as 0 (control), 200, 400, 600 and 800 mg kg-1 of feed) and fish were fed with satiation two times a day in RAS system for 90 days.
At the end of the trial, the results showed significant differences (p<0.05) in specific growth rate (SGR) in fish fed with dietary saponin 400 mg kg-1. The feed utilization, digestive enzyme activity, serum biochemical parameters, body composition, innate immune, and apparent digestibility coefficients of crude protein were not significant differences (p>0.05). Conversely, fish treated with diet contained saponin at 400 mg kg-1 of feed showed slight increase trends in PER and PG. The histopathological observation results in both liver and posterior intestine areas indicated no observable significant difference among the experimental groups. Moreover, fish fed control diet and inclusion of saponin at 400 mg/kg-1 was observed increase intestinal villi height. It is concluded that fish fed with diet supplemented saponin at 400 mg kg-1 tended to have better growth performance, feed utilization and physiological response.