Hormonal levels of estradiol, testosterone, and progesterone at entry into lay of year 1980 vs. 2000 broiler breeder females under fast and slow release from feed restriction

Eliyahu M. Heifetz, Israel Rozenboim, Morris Soller, Yoav Eitan*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


In the mid-1960s egg production, fertility, and hatchability of broiler breeder females dropped precipitously. Due to disrupted follicle hierarchies and development of the erratic oviposition and defective eggs (EODES) syndrome. EODES was controlled by restricting feed. In the 1990s, another set of problems arose at entry of broiler breeders into lay and characterized by high mortality followed by lower peak lay and reduction in egg and chick production. These problems are induced by even slight over-feeding, and hence we termed it the “Over Feeding Complex” (OFC). We have speculated that OFC is a quasi-EODES condition, induced by the intense selection for increased breast proportion. To test this, we compared, under fast (FF) and slow (SF) release from feed restriction, body composition and reproductive performance of a broiler breeder from year 1980 (B1980) and kept without selection for performance traits since then, to a line hatched in 2000 (B2000). During the first 16 d of lay, feeding treatment had little effect on egg mass or Laying % for the B1980 birds, while for the B2000 birds, SF treatment resulted in significantly greater egg mass and Laying % compared to FF, showing that the OFC indeed manifested in this experiment. However, contrary to hypothesis, follicle hierarchies were normal for both lines under both feeding treatments. To gain further insight into the OFC syndrome, we here report levels of estradiol, testosterone, and progesterone for these line and treatment groups in the time period leading up to and into lay. A significant line × feeding treatment interaction effect was found for estradiol and testosterone, to a lesser extent for progesterone. For all 3 hormones, for B1980 levels 2 to 3 wk post entry into lay were similar and intermediate under FF and SF, but differed significantly for B2000, being much greater under SF than under FF. Thus, the hormonal effects were parallel and may explain the egg mass and Laying % effects of FF and SF in the 2 genetic types.

Original languageAmerican English
Pages (from-to)3728-3735
Number of pages8
JournalPoultry Science
Issue number10
StatePublished - 2018

Bibliographical note

Funding Information:
©C 2018 Poultry Science Association Inc. Received September 1, 2017. Accepted April 29, 2018. 1Corresponding author: yoave@kv-yavne.co.il This research was supported by the US-Israel Binational Agricultural Research and Development Fund (BARD) and by the Israel Poultry Council.

Publisher Copyright:
© 2018 Poultry Science Association Inc.


  • Estrogen
  • Feed restriction
  • Feed × hormone interaction
  • Progesterone
  • Testosterone


Dive into the research topics of 'Hormonal levels of estradiol, testosterone, and progesterone at entry into lay of year 1980 vs. 2000 broiler breeder females under fast and slow release from feed restriction'. Together they form a unique fingerprint.

Cite this