Poultry feed availability and nutrition in developing countries Advances in poultry nutrition

Feed represents the greatest single expenditure associated with poultry production. nutritional research in poultry has therefore centred on issues related to identifying barriers to effective digestion and utilization of nutrients, and on approaches for improving feed utilization. Poultry nutritionists have increasingly combined their expertise with that of specialists in other biological sciences, including immunology, microbiology, histology and molecular biology. although broilers and layers are highly efficient in converting feed to food products, they still excrete significant amounts of unutilized nutrients. For example, in their manure, broilers lose almost 30 percent of ingested dry matter, 25 percent of gross energy, 50 percent of nitrogen, and 55 percent of phosphorus intake. there is therefore considerable room for improving the efficiency of feed conversion to animal products. Much of the inefficiency results from the presence of undesirable components and the indigestibility of nutrients in the feed. recent advances in poultry nutrition have focussed on three main aspects: i) developing an understanding of nutrient metabolism and nutrient requirements; ii) determining the supply and availability of nutrients in feed ingredients; and iii) formulating least-cost diets that bring nutrient requirements and nutrient supply together effectively. the overall aim is precision feeding to lower costs and maximize economic efficiency. in the past, there was a tendency to overformulate diets when there was doubt about the availability of critical nutrients (especially amino acids and phosphorus) or when nutrient requirements were uncertain. this practice is no longer acceptable, not only because it is wasteful, but also because excess nutrients excreted in the manure are ultimately a source of pollution. Fine-tuning diets so that they more closely match the requirements of the birds, helps to optimize the efficiency of nutrient utilization. the major developments towards achieving the goal of precision feeding are discussed in the following sections.