Livestock industry in Nigeria is ridden with myriad of problems, which have resulted to a gross shortage of meat and other animal products (Nworgu, 2002). The animal protein intake shortages in Nigeria observed in the early 1970s has progressively worsened till date. The protein intake of an average Nigerian is about 53.8g with only 6.0 – 8.4g per caput per day of animal origin (Egbunike, 1997). CBN (2003) revealed that North America, Western and Eastern European countries consume 66, 39 and 33g of animal protein per head per day respectively; while an average Nigerian consumes 7.5g which is below the recommended level of 27g per caput per day. The sub-optimal consumption of animal protein by a large percentage of Nigerian population has challenged not only livestock farmers, but also researchers and policy makers.
Poultry industry is one of the major sources of animal protein and offers the potential for bridging the protein deficiency gap existing in the country. However, the inadequate supply of several grains and protein concentrates for poultry feeding and the keen competition between man and animal for same have become the major obstacle in poultry industry development in Nigeria (PAN, 1985; Ologhobo, 1992). Feed constitute the dominant input in animal production ranging from 65-75% of the total cost of production. Similarly, feed ingredients account for over 90% of compound feed industry. Therefore, the relationship between feed ingredient and animal product output is both direct and obvious. To depend on alternative sources of ingredients, especially when it encourages a shift to ingredients for which there is less competition, may help if the later is cheap and sufficiently available (Oluyemi and Roberts, 1979). The future of efficient and profitable poultry production would, therefore, depend on finding cheaper and alternative energy and protein sources to conventional protein and energy feed ingredients.
Recently, much effort is being made to find the possibilities of utilizing agro-industrial by-products in poultry nutrition (Henuk and Dingle, 2003). This could lead to the reduction in the use of conventional feed ingredients such as maize, soybean, sorghum, groundnut, wheat etc (El Boushy and Van der Poel, 2000) and help reduce pollution problems, decrease feed cost and increase livestock production.
Agro-industrial by-products in Nigeria vary from primary processing of farm produce wastes to wastes from agro-allied industries. Some of these wastes are left unutilized, which often cause environmental pollution and hazard. Those that are utilized do not have their full potentials harnessed. Agro-industrial by-products which can be of tremendous use in the livestock industry for feeding animals include maize pap waste and rice milling waste etc.
Since energy is one of the most expensive segments of a poultry ration, accurate knowledge of the available energy content of feedstuffs is necessary to formulate the most economical least-cost rations and to achieve profitable production. Supplying adequate energy to birds is one of the most important aspects of successful management program. It is by knowing and meeting the nutrient requirements of the bird that their full genetic potentialities can be realized.
Apparent metabolizable energy (AME) is the most widely used method for evaluating poultry feedstuffs for available energy. However, since Sibbald (1976) developed a bioassay for true metabolizable energy (TME), a considerable amount of research has been conducted to investigate the assay’s applicability. Sibbald’s method has several advantages over the previous AME assays. It is simple, rapid, and inexpensive. Besides its reported flexibility, reproducibility, and data quality (Sibbald, 1976), the TME assay can be extended to measure bioavailable amino acids (Likuski and Dorrel, 1979; Sibbald, 1979) and lipids (Sibbald and Kramer, 1978) in feedstuffs.
Although literature is replete of the importance of energy in poultry nutrition, there are two feedstuffs of regional interest that require evaluation for their nutrient composition especially their energy content. For such feedstuffs, knowledge of their available energy will enhance their usefulness in poultry feeding.