VOL. 7, NO. 7, JULY 2012 ISSN 1990-6145 ARPN Journal of Agricultural and Biological Science © 2006-2012 Asian Research Publishing Network (ARPN). All rights reserved. www.arpnjournals.com 497 EVALUATION OF YAM-SWEET POTATO PEELS MIXTURE AS SOURCE OF ENERGY IN BROILER CHICKENS DIETS Diarra S. S., Igwebuike J. U., Kwari I. D., Sinodo S., Babangida A., Ahmadu U., Shettima S. and Jibrin M. Department of Animal Science, University of Maiduguri, Maiduguri, Nigeria E-Mail: siakadiarra@yahoo.com ABSTRACT In the search for alternative energy sources for poultry feeding, a 9-week experiment was conducted to ascertain the replacement value of yam-sweet potato peels mixture (YSPPM) for maize in broiler chickens diets. One hundred and eighty (180) Anak-2000 broiler chicks aged 6 days were randomly assigned to 12 floor pens containing 15 birds each. Four diets, based on 23 and 20% crude protein in the starter and finisher respectively, were formulated to contain 0, 15, 30, and 45% YSPPM as replacement for maize grain. Each of the diets was fed to 3 pens of 15 birds in a completely randomized design. Data were collected on growth indices, haematological profile, and carcass measurements and organs weights. During the starter period (7-28 days), daily feed intake and feed cost/kg gain were not adversely affected by feeding the test ingredient, but weight gain and feed conversion ratio (FCR) were depressed above 15% replacement of maize with the test material. In the finisher phase (28-63 days), feed intake was significantly increased on the 45% replacement diet compared to the control but did not differ statistically amongst the YSPPM-based diets as well as amongst the control, 15 and 30% replacement diets. The highest daily gain was recorded on the 15% replacement diet, but its values did not differ markedly amongst the control, 30 and 45% diets. Feed conversion ratio was significantly increased above 15% replacement of maize with YSPPM. Feed cost per kg gain was significantly reduced on the 15 and 45% replacement diets. The results of haematology did not show any depressive effect of feeding YSPPM. Similarly, the results of carcass measurements and organs weights did not show any disadvantage of feeding YSPPM, but there were beneficial effects of its feeding over the control maize-based diet with respect to breast meat and abdominal fat deposition. It was concluded that YSPPM can replace maize up to 15 and 45% in broiler starter and finisher diets respectively without adverse effects on the growth, haematological profile and carcass measurements. Keywords: broiler chickens diet, yam-sweet potato peels mixture, maize, alternative energy sources. INTRODUCTION The scarcity and high cost of cereal grains, especially maize, has necessitated research into alternative energy sources for feeding poultry. Sweet potato (Ipomea batatas) and yam (Dioscorea rotundata) are produced in large quantities in Nigeria and form important energy sources for human and livestock feeding. The peels from the processing of these roots are readily available at cheap costs in many parts of the country because they have limited or no human food value. Yam peel meal (YPM) is reported to be a good source of protein [1, 2] but poor in energy [1, 3]. On the other hand, sweet potato peel meal (SPPM) is high in energy but low in protein [4]. Mixing SPPM and YPM (50:50) will therefore, give a product with intermediate protein and energy contents. Although YPM and SPPM have been used singly to replace part of dietary maize, replacement levels have not been high in broiler diets. At the moment, there is no literature on the feeding value of the mixture of the two peels to poultry. This study reports the effect of feeding yam- sweet potato peels mixture (YSPPM) as a source of dietary energy on broiler chickens’ performance. MATERIALS AND METHODS Study site The study was conducted at the Poultry Unit of the University of Maiduguri Livestock Research Farm between September and November, 2011. The area falls in the semi-arid zone with an annual rainfall of 500-600mm [5]. Sweet potato and yam are very important energy sources in human diets and their peels are readily available because they have little or no human food or industrial uses in the area. Source of the test materials Sun-dried peels (sweet potato and yam) were purchased from restaurateurs in Maiduguri Metropolis, further allowed to dry in the sun for 72 hours and ground separately in a hammer mill to pass through a 40-mesh sieve. The ground peels were then mixed in the ratio of 50:50 weights for weight to produce yam-sweet potato peels mixture (YSPPM) which was analyzed for proximate composition (Table-1) and used in the formulation of the experimental diets. Experimental birds and diets Two hundred and forty (180) day-old Anak-2000 broiler chicks purchased from Obasanjo Farms, Otta, Nigeria, were brooded together for the first 6 days during which they were fed a commercial starter diet from ECWA feeds, Nigeria. On the 7 th day, the chicks were weighed and randomly allotted to 4 diets/treatments containing 3 replicates of 15 chicks each of similar weight (100 ± 0.2g/bird). Each replicate was housed in a floor pen measuring 1.95m 2 with wood shaving on the floor as litter material. The birds were vaccinated against Gumboro