Evaluation of growth, survival rate, feed utilization, and economics of Oreochromis niloticus fry fed on diets containing alternative protein sources for fish meal [electronic resource].

Includes reference.

A total number of 180 Nile tilapia (Oreochromis niloticus) fry (average body weight was 3.0 g/fish) were randomly divided to six experimental groups (30 in each) in three replicates (10 in each) to evaluate the use of different protein sources in combination with protein-rich ethanol by-product from corn (pbc) with or without source for mixture of methionine plus lysine (limiting essential amino acids) in feeds for Nile tilapia fry on, growth performance, feed utilization and economics. The control diet (T1) contained fish meal and soybean meal as the main protein sources. Each tested diet (T2-T6) contained 35%pbc (by weight), in combination with fish meal and soybean meal (T2), herring by-product and soybean meal(T3), T3 plus 300mg/100g diet mixture of methionine plus lysine (T4), soybean meal alone (T5), T5 + 300mg/100g diet mixture of methionine plus lysine (T6). All diets (T1-T6) were isonitrogenous (30% crude protein) and isocaloric (330Kcal DE/100g diet). Tilapia were fed 4% of its body weight twice daily for 90 days (experimental period). The obtained results revealed that, no significant differences (p>0.05) in growth performance were observed between among tilapia fed diets T2,T3,T4 and control(T1).Tilapia fed diets T5 and T6 had significantly (p>0.05) lower in growth performance than other experimental diets (T1- T4).Also, tilapia fed diet T5 had significantly lower in feed conversion ratio(FCR) than other experimental diets. Cost per unit weight gain for diets T2, T3, T4 and T6 were less expensive than control diet. But, cost per unit weight gain for diet T5 was significantly (p>0.05) higher than control diet. This data suggested that, efficient and economical tilapia growth can be obtained by feeding diets without fish meal by using combination of protein-rich ethanol byproduct, herring by-product and soybean meal with or without mixture of methionine plus lysine under experimental conditions.

Summary in Arabic.

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