Soybean Flour - Poultry Meat Meal Blend as Dietary Protein Source in Practical Diets of Oreochromis niloticus and Clarias gariepinus

Abstract

Two parallel experiments were conducted to evaluate the utilization of defatted and toasted soybean flour (SF) blended with poultry meat meal (PMM) as a dietary protein source in the practical diets of Oreochromis niloticus (M±SE = 8.2±0.5 g) and Clarill'S gariepinus (M±SE 19.4±1.8 g) fingerlings. They were fed four isonitrogenous and isoenergetic diets containing blends of SF and PMM in ratios of 25:75, 50:50, 75:25 and the reference diet (100:00) for eight weeks, at 4% body weight per day. A trend of difference in nutrient utilization was observed in both investigations as diet II (50:50) recorded better food conversion ratio, specific growth rate, and protein efficiency ratio than any other diet. These differed significantly with the diets (P<0.10). This was probably as a result of a better and an ideal essential amino acid balance in the diet than any other one. There was increase in the level of sulphur containing amino acids (methionine + cystine) with increasing incorporation of PMM as blend with SF in all the diets except the reference diet (without PMM). This order was reversed for phenylalanine + tyrosine, and leucine that was in excess. Methionine deficiency and excessive leucine were ameliorated while phenylalanine + tyrosine level decreased. Carcass composition differed significantly with respect to the diets only in 0. niloticus (P<0.05). Carcass lipid and ash increased with increasing levels of PMM.