title: Reproductive senescence in domestic fowl: effects on egg production, sequence length and inter-sequence pause length.
abstract: 1. Age-related changes in egg production, oviposition sequence length and inter-sequence pause length were studied by analysis of oviposition records of 50 individually-caged broiler breeders from 24 to 62 weeks of age. 2. The 44 surviving hens exhibited a production profile characteristic of broiler breeders (184 eggs per hen), with a peak mean sequence length of 19 eggs at 32 weeks of age. Inter-sequence pause length was maximum (1.6 d) at 54 weeks of age. Overall, the hens averaged 48 sequences, with a mean sequence length of 4.1 d. 3. Most hens had a single characteristically long sequence about the time of peak egg production (average: 24.3 d). The term 'prime' is suggested to denote this sequence. 4. Sorting the hens into groups on the basis of total egg output (upper and lower 50% and upper and lower 25%) indicated that high producing hens (upper 50% and 25%) had a very long prime sequence early in lay, and had few inter-sequence pauses of greater than 1 d duration. The converse was true for low producers (lower 50% and 25%). 5. The length of the prime sequence may be a good indicator of reproductive efficiency of hens later in life.
authors.affiliation: Department of Animal Science, University of Alberta, Edmonton, Canada.
authors.forename: F E
authors.initials: FE
authors.lastname: Robinson
authors.forename: R T
authors.initials: RT
authors.lastname: Hardin
authors.forename: A R
authors.initials: AR
authors.lastname: Robblee
mesh_terms: D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D000818:Animals; D002645:Chickens / Q000502:physiology*; D005260:Female; D010058:Oviposition / Q000502:physiology*; D013997:Time Factors