Metabolizable Energy Values of Dried Leaves of Cassava (Manihot Esculenta), Siam Weed (Vernoma Amygdalina), and Bitter Leaf (Chromolaena Odorata) for Broiler Chickens

1.0 Introduction
Global consumption of poultry products, especially poultry meat has consistently increased over the years and the trend is expected to czontinue. Much of the increase in global demand for poultry industry is having a profound effect on the demand for feed and raw materials. However, it is also becoming clear that the requirement for the four traditional (conventional) feed ingredients cannot be met. The gap between local supply and demand for these traditional ingredients is expected to widen over the coming decades, providing a compelling reason for exploring the usefulness of locally available alternative feed stuffs in feed formulations. In Nigeria, commercial poultry production is one of the highest sources of animal protein, but the challenge faced by the industry mainly is the availability, on sustainable basis, of feed and feed ingredients. Thus making alternative feedstuff an option to be given a serious and concerted consideration, since they are most times relatively cheaper and readily available.
Alternative feed ingredients can be whole products, by products processing industries. They can as well be part of a crop that is not mainly the reason of planting the crop, like the leaves of tuberous crops. Unconventional feed ingredients possess the advantage of low cost, ease of accessibility and low food-feed competition. Leaf meal obtained from otherwise less used leaves like cassava leaf and bitter leaf; and from a ‘nuisance' weed Chromolaena odorata (Siam weed)have obvious potential in poultry diet, but their use have been negligible owing to constraints imposed by nutritional, technical and social factors. Nutritional factors like variability in nutrient quality; limited information on the availability of nutrients, high fibre content, presence of anti-nutritional factors, while amongst the technical factors include are seasonality; bulkiness, processing, detoxification and limited research and development facilities for determining nutrients composition and inclusion levels in poultry diets.
The socio-economic aspect include competition with use as human food, poor prices relative to other arable crops (Farmers interest), cost per unit of energy or limiting amino acid, relative traditional feedstuffs (Feed manufacturer's interest), and cost of processing. There has been keen interest in evaluation alternative feed resources over the years, and a proliferation of published data especially from developing nations.
However most of these research works on the use of alternative feedstuff are concerted on their proximate composition with little emphasis on their energy composition determination. Energy determination, especially metabolizable energy is necessary since the relationship between energy requirement and intake is the cornerstone of practical diet formulation. By combining feedstuffs to produce diet with predetermined nutrient, energy ratios, the intake of nutrients can be regulated. The effectiveness of diet formulated is this determine by accuracy and precision of the data describing the energy requirement of poultry and available energy concentrations in feeds.