Critique and review of methods of digestibility evaluation in nutrition studies -digestibility of soybean flour, poultry meat meal and wheat flour in Oreochromis niloticus and Clarias gariepinus as case studies

Abstract

The digestibility of soybean flour (SF), poultry meat meal (PMM) and wheat flour (WF) in Oreochromis  niloticus and Clarias gariepinus were investigated. There was no significant difference in the nutrient  apparent digestibility coefficient (ADC) of the test and reference diets (p>O. 05). The dry matter, protein, lipid  and ash A DCs were high in the d ets and that all test diets were as digestible as the reference diet. The protein of SF test diet was more digestible than that of the reference diet in O. niloticus. Similarly, the dry matter and the ash of PMM test diet were more digestible than those of reference diet in O. gariepinus. These were about 100% digestable. 30% replacement of the reference diet gave a test diet whose proximate composition differed markedly with that of the test feedstuff being evaluated and insignificantly with that of the reference diet. This was considered inappropriate and therefore suggested that a much higher level of replacement be considered in digestibility study.

Keywords: Digestibility, Soybean flour, Poultry meat meal, wheat Oreochromis niloticus, Clarias  gariepinus,flour,