Abstract
The demand for poultry products has consistently increased over the years as a result of the increasing world population and presumed health benefits of poultry products. Alternative cheaper ingredients for poultry feed is a widespread need in developing countries because maize, the traditional source for poultry energy, is scarce and expensive. During processing of roots and tubers for food and industrial uses, large quantities of peels are produced which are of low economic value and may cause environmental pollution if not disposed of responsibly. One way of utilising peels efficiently could be as poultry feed ingredients. This study reviews the utilisation of yam peels in poultry feeding with emphasis on the chemical composition and prospects. Yam peels from two varieties of Dioscorea rotundata (Puna and Punjo cultivars) were made into flour by hot air drying (60oC, 24h) and milled to flour. The nutritional and structural properties of the yam peels were determined by standard AOAC methods and scanning electron microscope (SEM). The nutritional compositions on dry weigh basis for puna and punjo yam were: moisture (3.56%, 4.6%); ash (4.81%, 5.01%); fat (0.59%, 0.70%); protein (6.56%, 6.58%); crude fibre (5.04%, 5.16%) and carbohydrate (78.71%, 79.09%), respectively. The carbohydrate consisted of starch (66.61, 67.94%) and sugars (14.88, 15.42%). The puna yam starch granules were cylindrical in shape while punjo yam starch granules had triangular shapes. The granules was not smooth which may be due to adhering proteins, polysaccharides and fats in the yam peel flours. The nutritional composition of the yam peels makes them potential ingredients in poultry diets because of their fibre and protein content. The protein content of yam peels may be enriched further by fermenting them with edible fungi such as Saccharomyces cerevisiae to produce protein enriched value-added products for poultry feeding.