INFLUENCE OF USING BY-PRODUCT ROCKET SEED MEAL (ERUCA SATIVA MILLER) IN NILE TILAPIA (OREOCHROMIS NILOTICUS) DIETS ON GROWTH PERFORMANCE

AND FEED UTILIZATION.

Medhat E.A. Seden

Department of Fish Nutrition, Central Laboratory for Aquaculture Research CLAR, Agriculture Research Center, Egypt.

Received 7/ 10/ 2014

Accepted 23/ 11/ 2014

Abstract

This study was carried out to determine the effect of different by-product rocket seed meal (BRSM) (Eruca sativa Miller) levels as a feed additive in fish diets on growth performance, feed utilization and economic efficiency of Nile tilapia (Oreochromis nilotcus) fingerlings (4.1±0.05g/fish). Six experimental diets were formulated to contain 0.0 (control), 0.1, 0. 2, 0.3, 0.4 and 0.5 % by-product rocket seed meal (BRSM). Diets were isonotrogenous (30% crud protein), isolipidic (7.5% total fat) and isocaloric (4.48kcal/100g). Each diet was fed in triplicate groups two times a day for 12 weeks at feeding level of 4% of fish body weight. Results revealed that final weight, weight gain and growth rate (g/day) increased significantly (p<0.05) with increasing BRSM levels in diets. Highest growth was obtained in fish fed at diets containing 0.4 and 0.5% BRSM without significant differences, while the lowest growth was obtained in fish fed at control group diet. Survival rate slightly enhanced with the addition of inclusion of BRSM in fish diets without significant differences (p<0.05) among treatments. Highest feed intake and best FCR value were obtained at fish fed at diets containing 0.4 and 0.5% BRSM without significant differences. Protein efficiency ratio (PER), Feed efficiency ratio (FER), Apparent protein utilization (APU), Specific growth rate (SGR) and Energy utilization (EU) values were improved significantly (p<0.05) with the addition of inclusion of BRSM in fish diets, maximum values were obtained at fish fed at diets containing 0.4 and 0.5% BRSM without significant differences, while the lowest were obtained at control group. Dry matter, crud protein and total lipids improved significantly (p<0.05) with increasing BRSM levels in fish diets. There was a reduction in feed cost to produce 1kg of fish gain with 16.84 % & 16.94% in fish fed at diet containing 0.4 and 0.5% BRSM without significant differences compared to control diet. In conclusion the result of the present work suggest that supplementing diets with By-product rocket seed meal at the level of 0.4% improved growth performance, feed utilization and reduction the feed cost of Nile tilapia fingerlings.

Key words: By-product rocket seed meal, Nile tilapia, growth performance, feed utilization.