Similarly, Shim and Pesti (2011) also reported that changes in the incubation temperature of as little as 1°C during embryonic d 4 to 7 affect chick initial BW and they found hatching chick weight of 49.0, 49.6, and 50.6 g in lower (36.5°C), control (37.5°C), and higher (38.5°C) incubation temperatures, respectively.