Effect of different photoperiods on some maintenance behavior, external and internal egg quality traits of layersEffect of different photoperiods on some maintenance behavior, external and internal egg quality traits of layersAA0069128X
S142 , 2016-04 , Graduate School of Veterinary Medicine, Hokkaido University
This study was conducted to investigate the effect of three different photoperiods (13, 16, 19 hours) on some maintenance behavior, external and internal egg quality traits of layers. One hundred and eight birds of Bovans layers at 25th week of age were used. The birds were divided randomly into three equal groups and each group subdivided into 6 replicates (6 bird / one replicate), where the cages floor spaces were 833 cm2 / bird. The obtained results revealed that the birds housed at 16 hours of photoperiod/day laid egg with significant (P<0.05) higher external quality traits, including egg length, egg width, shell weight, egg shell ratio and shell thickness than other groups. Moreover, egg weight and its surface area were significantly higher in 16 hours light than 13 hours. Similarly, the most of internal quality traits, including yolk height, albumen height, yolk weight and yolk ratio. In addition, there was an increase in the most of behavioral patterns (feeding, drinking, sitting and other comfort behavior) in16 hour's photoperiod, with significant differences. It was concluded that, there is an economical effect of housing layers at different photoperiods.