The Effect of Dried Sweet Potato (Ipomea batatas) Vines on Egg Yolk Color and some Egg Yield Parameters

Effects of dried vines powder of sweet potato cultivars 'Hatay Beyazi', 'Hatay Kirmizi' and 'Beauregard' on egg yolk color were determined in layers aged 44-52 week. In this study, 176 layers were equally divided into 11 groups including negative control (no pigments), positive control (commercial layer diet) and three sweet potato varieties with three doses (3 x 3) at 15, 20, 25 mg/kg total xanthophylls. The internal and external quality characteristics of the Monday and Thursday eggs were recorded. Egg yolk score were classified by visual with Roche Color Fan (RCF) and Minolta refractometer. Egg production, feed intake, live weight and feed conversion ratio were calculated weekly. The highest RCF value 3.96 was obtained from those fed with 'Hatay Kirmizi'. The greatest a and b values were recovered at the 25 mg/kg dose of 'Hatay Kirmizi' compared to the other sources. In conclusion, to obtain the desired level of RCF values in the egg yolk, the dried vines powder of 'Hatay Kirmizi' having natural carotenoid content can be used as a natural pigmenter in layer diet. (C) 2011 Friends Science Publishers