Effect of Partially Replacing Corn Meal by Date Stone on Growth Performance in Nile Tilapia Fingerlings, Diets Supplemented with Marjoram: Effects of Date Stone on Growth Nile Tilapia

Abstract

A 3-month randomized factorial design 4x2 (four levels of Date stone (DS) (0, 15, 30, and 45%), two levels (0 and 0.03%) of Marjoram (M) and three replicates). The trial was conducted in twenty four glass aquaria. Ten fingerlings of Nile tilapia were placed in each aquarium with an average weight 15.40 ± 0.3 g fish. Fish were fed twice daily (six days a week) at a rate of 3% of body weight. The results revealed that, mean final weight (g/fish), SGR (% /day), feed conversion ratio, PPV and PER, were significantly (p ≤ 0.05) affected by the levels of DS and level of M. And the best diet achieved which contain 15% DS and supplemented with 0.03 % M was not significantly different from control diet in fish performance. From the above results and the economic information of these study it can be concluded that, diet containing 15% of DS with 0.03% M exhibited the highest net profit and would seem to be the most desirable level of DS and M in the system studied.