CHAPTER ONE 1.0 INTRODUCTION
poultry manure with high protein content (80%-85%) and is commercially available. With some chemical treatment, feather meal can be a good source of sulfur-containing amino acids [11]. A dietary feather meal inclusion of not more than 25% in the diet of catfish fingerlings has been reported by Serwata and Davies [12]. When feather meal is hydrolyzed and mixed with chicken offal and maggot meal, the mixture was able to replace 50% of fi sh meal used in African catfish fingerlings’ diets without causing any adverse effects on fish growth [13]. Maggot meal is high in biological value and contains ten essential amino acids [14] that are comparable to fi sh meal [15] and high in nutritive value. The biological value of poultry manure meal is equivalent to that of fish meal and maggot larvae contained no anti-nutritional or toxic substances found in alternative protein sources of vegetable origin [16].
1.1 BACKGROUND OF THE STUDY
The African catfish Clarias gariepinus is a major warm water species in Africa (Ghana, Ethiopia, Egypt, Mali and Nigeria) and Asia (Malaysia, the Philippines and Thailand) and has been introduced recently in Europe (the Netherland, Germany and Belgium) Latin America (Brazil) (Food and Agriculture Organization, FAO, 1997; Ali, 2001). The superior performance of C. gariepinus compared with other Clarias species in terms of growth rate has probably contributed to the fact that C. gariepinus has been widely introduced to areas outside its natural range (Verreth et al., 1993). Fish culture has rapidly intensified in the last few decades, at an average rate of 8-10% per year (Tacon et al., 2011). To sustain this growth in aquaculture, an associated problem is the supply of ingredients to formulate aquatic feeds, and in particular dietary replacements for fishmeal.
African catfish is a suitable alternative to tilapia for subsistence fish farming in Africa and using low-grade feed composed of local agricultural by-products, the yield of catfish from ponds could be as much as 2.5 times higher than those of tilapia (Hogendoorn, 1983). A variety of species of genus Clarias and their hybrids were cultured for reasons of their high growth rate; disease resistance and ability to adapt to high density culture; excellent adaptation to high ambient climate and very efficient feed conversion ratio; ability to mature and remain grand throughout this year in captivity; acceptance of relatively cheap feeds; high fecundity potential for all-year round maturation and induction of final oocyte and high consumers’ acceptance (Viveen et al.,1985).
The increasing cost of fish feed has made research interest to be focused on reducing cost of the most expensive ingredients by alternative protein sources. Since most of the research have been conducted for replacing fish meal with either plant protein sources or other un-conventional animal protein sources (Wee and Wang, 1987; Adeparusi, 1993; Keembiyehetty and Desilva, 1993; Martinez –Palacios et al., 1998; Faluroti et al., 1998). On the contrary fewer works have been reported on the replacement of soyabean meal which is the costliest and the the most utilized plant protein source in most fish feed (Lovell, 1988) in developing countries (Alexis, 1990).
Poultry manure is a potential source of protein. It has attracted the attention of animal nutritionists all over the world because of its richness of protein, calcium (5.4%), phosphorus as K2O and magnesium as MgO (0.335%) other minerals (Ranjhan, 1980; SPFG, 1994). Recently, fish farmers especially in the integrated farming system have been encouraged to recycle wastes from animal dung (especially poultry) as food for fish rather than discard them. Poultry manure is not only used as organic manure in the production of plankton but also directly consumed by
fish in the culture system. Although, this observation has been verified by many workers (Oladosu et al., 1990; Gavina, 1994; Ogunba and Abumoye, 1998), information on the effect of the dung when incorporated into artificial fish diets are scarce.