title: The effects of cooling the egg on the respiratory movements of the hatching duck (Anas platyrhynchos).
abstract: 1. The ambient temperature of pipped eggs of the domestic duck was reduced from 39 degrees C to 24 +/- 1.5 degrees C for a period of 1 hr. 2. In the majority of embryos there was a notable increase in the amplitude of respiration. 3. The respiratory frequency of each embryo fell, but remained above a value of 60 breaths/min. 4. When the eggs were rewarmed there was a reduction in the respiratory amplitude within a period of 10 min and the respiratory frequencies of the majority of embryos returned to normal within a period of 30 min. 5. These results are compared with those obtained previously in similar studies on the domestic fowl and quail.
mesh_terms: D000818:Animals; D003080:Cold Temperature; D004372:Ducks / Q000502:physiology*; D004531:Eggs; D012119:Respiration; D013696:Temperature; D013997:Time Factors; D014828:Vocalization, Animal / Q000502:physiology