Effect of High Thermal Manipulations during Early and Late Embryogenesis on Asymmetry for Broilers

The aim of this study was to determine the effect of thermal manipulations during early and late embryogenesis on asymmetry in terms of sides of shank length, shank width and face length of broilers. Incubation conditions were 37.5°C and 55% relative humidity for control group throughout the incubation period until the 19th days. In the thermally treated eggs during early embryogenesis (8-10 days), incubation temperature was increased to 41°C and relative humidity to 65% for 3 hours (12.00-15.00) on the 8th-10th days of incubation. Also, in the late embryogenesis stage (16-18 days) incubation temperature was increased to 41°C and relative humidity to 65 % for 3 hours (12.00-15.00) on the 16th-18th days of incubation. Total 16 chickens were selected at randomly from all experimental groups to determine the asymmetry. The weekly left and right sides of shank length, shank width and face length of chickens were measured from 7 days of age to 35 days of age, and relative asymmetry values were calculated. There was no significant difference among the groups in point of relative asymmetry. Asymmetry values were reduced due to aging.