Optimum protein requirement for the growth of Jelawat fish (Leptobabrbus hoevenii)

A study was conducted to evaluate the growth performance of juvenile Jelawat fish, Leptobarbus hoevenii, fed 4 levels of crude protein (CP): 25, 32, 38 and 44% with isocaloric diets of 15.20 MJ/kg. All experimental feeds were formulated using digestible protein values of local feedstuffsnamely poultry offal meal, palm kernel expeller and rice bran. The fish were reared in 1000-litre circular polytanks with 3 replicates with 50 fish per replicate per diet. The feeding trial was conducted for 168 d from fingerling stage of 7.62 cm to 25.40 cm in size. Fish fed 38% CP showed the best growth performance in terms of weight gain (39.86 g), feed conversion ratio (1.70) and specific growth rate (0.72) but were not significantly different (P>0.05) from fish fed 32% and 44%. Lower protein levels used in the experimental diets resulted in lower performance of the Jelawat fish. The lowest protein efficiency ratio (PER) was found in fish fed with 44% CP, and as the protein level in the diet increased, the PER value decreased. Feed formulated with 38% CP was found to be the optimum protein level needed for the growth of Jelawat fish