The Pattern of Egg Laying in Turkeys

THE cyclic pattern of egg laying in the domestic fowl has received considerable attention from a number of investigators. Atwood (1929), who defined “clutch” as a group of ovipositions on successive days, found that the first egg of a clutch (or cycle) as a rule is laid in the morning. He also observed that the average time interval between successive eggs in a clutch is about 26 hours; this accounts for the fact that each successive egg is laid later in the day than the previous one. Atwood suggested that the clutch is terminated when an oviposition is scheduled to take place late in the afternoon. It is a common observation that hens normally do not lay after onset of darkness. Both Atwood (1929) and Heywang (1938) found that the time intervals between eggs within clutches tend to be characteristic for individual hens. Atwood (1929) and Berg (1945) also demonstrated . . .