Evaluation of guar seed as a protein source in Nile tilapia, Oreochromis niloticus (L.), practical diets

An 84-day feeding trial was conducted with juvenile (6.9 g) Nile tilapia. Oreochromis niloticus (L.), to investigate the effects of replacing fish meal with the legume guar seed as a protein source in practical diets. Four isonitrogenous (32% crude protein) and isocaloric (3.5 kcal DEg(-1) diet) diets were formulated. The replacement levels for guar were 25%, 50% and 75%, The reference diet contained fish meal as the main protein source and no guar. The growth performance, feed conversion ratio and protein efficiency ratio were significantly better in fish fed diets with 25%, 50% and 0% guar than in fish fed the 75% guar diet. The results of the present study suggest that effective replacement of fish meal protein by guar seed protein up to the level of 50% is possible in tilapia practical diets without any adverse effects on growth and feed conversion ratio.