AGRICULTURE AND BIOLOGY JOURNAL OF NORTH AMERICA ISSN Print: 2151-7517, ISSN Online: 2151-7525, doi:10.5251/abjna.2015.6.1.30.33 © 2015, ScienceHuβ, http://www.scihub.org/ABJNA Bone characteristics of broiler chickens fed diets supplemented with graded levels of vitamin C Olugbenga Adeniran Ogunwole Animal Nutrition Unit, Department of Animal Science, University of Ibadan, Ibadan, Nigeria Corresponding author's E-mail: droaogunwole@gmail.com ABSTRACT A 42- day trial was carried out to investigate the bone characteristics of broiler chickens fed graded levels of ascorbic acid. Six experimental diets were formulated; the control diet T1 was without vitamin C while five other diets contained 0.1(T2), 0.2 (T3), 0.3 (T4), 0.4 (T5) and 0.5 % (T6) ascorbic acid. A total of 270 one-day old broiler chicks were allotted randomly to the six diets each in triplicate of 15 chicks per replicate. The diets and water were offered to the respective birds ad libitum. The design of the experiment was completely randomized design. The physical characteristics of bone were not significantly affected (p>0.05) by dietary vitamin C inclusion. Bone ash (%) of broilers fed T1 (64.99), T2 (65.31), T3 (65.75) and T6 (65.01) were lower (P<0.05) compared to those on T4 (66.12) and T5 (66.03). All measured chemical indices of broiler bones significantly varied (P<0.05) by increased vitamin C inclusion. Regressions of dietary vitamin C concentration on bone minerals deposition were all positive and highly significant. Ascorbic acid supplementation in the diet may therefore be of profound benefit to the chemical composition of bone in broiler chickens. Keywords: Vitamin C supplementation, Bone mineralization and strength, Tibia ash, Broiler chickens INTRODUCTION Bone problems have been identified (Rath et al., 2000) as one of the main production and health concerns in meat-type poultry. Rapid growth results in skeletal deformities including problems caused by leg weakness that result in lameness and consequently poor animal welfare (Sanotra et al., 2001). It was postulated that modern poultry has been bred for superior meat production, possibly overlooking the consequences on bone quality (Rath et al., 2000). Dietary ascorbic acid have been of extensive use in stress management in broiler production (Vansudevan et al., 2011; Majekodunmi et al., 2013; Ogunwole et al., 2013a; Majekodunmi, 2014). Other roles which include collagen formation, nutrient absorption, anti- oxidant functions etc. have been documented (Bhattacharya, 2010; Cheeke and Derenfeld, 2010; Vansudevan et al., 2011). Ascorbic acid inclusion in the diet to maximize broiler chicken production in temperate region has been documented (McCormack et al., 2001). Majekodunmi et al. (2012) also reported that ascorbic acid supplementation in water for heat stressed broilers in Ibadan, Nigeria, increased survivability though did not positively affect the body weight and feed conversion ratio. Emphases have thus been much on chickens performance (Ogunwole et al., 2013b), blood profile (Ogunwole et al., 2013a) and physiological responses (Majekodunmi, 2014) with little attention to the effects on bone characteristics of broilers (Newman and Leeson, 1999; Lohakare, 2005). This study was therefore aimed at investigating the effect of graded dietary supplementation of vitamin C on bone characteristics of broiler chickens. MATERIALS AND METHODS The experiment was undertaken at the Poultry Unit, Teaching and Research Farm, University of Ibadan, Ibadan Nigeria using 270 one-day old Arbor acre broiler chickens. Birds were weighed and randomly allotted to six treatments. Each treatment was replicated three times with 15 birds per replicate in a completely randomized design. The birds were raised on conventional deep litter open sided house. Formulated broiler starter and finishers’ diets contained 3142 KCal/Kg ME and 22.9% CP; 3116 KCal/Kg ME and 19.69% CP respectively. Diet T1 -