Effect of embryonic thermal manipulation on heat shock protein 70 expression and immune system development in Pekin duck embryos

ABSTRACT Two experiments were conducted to study the effects of thermal manipulation on heat shock protein 70 (HSP70) transcription and immune cell characteristics’ in Pekin duck embryos. In experiments I and II, fertile duck eggs were incubated at either a standard (S; 37°C) or high (H; 38.0°C) temperature from embryonic day (ED) 1 to 10. At ED11, half the eggs incubated at 37.5°C or 38.0°C were either kept at 37.5°C (SS) or 38.0°C (HH) respectively, or moved to the opposite incubator/temperature of either 38.0°C (SH) or 37.5°C (HS). Beginning on ED 21, all eggs (embryos) were incubated at 37.5°C. In experiments I and II, the mean egg shell temperature (EST) of eggs incubated at 38.0°C was higher than that from 37.5°C at ED10 (P