Know more

Our use of cookies

Cookies are a set of data stored on a user’s device when the user browses a web site. The data is in a file containing an ID number, the name of the server which deposited it and, in some cases, an expiry date. We use cookies to record information about your visit, language of preference, and other parameters on the site in order to optimise your next visit and make the site even more useful to you.

To improve your experience, we use cookies to store certain browsing information and provide secure navigation, and to collect statistics with a view to improve the site’s features. For a complete list of the cookies we use, download “Ghostery”, a free plug-in for browsers which can detect, and, in some cases, block cookies.

Ghostery is available here for free:

You can also visit the CNIL web site for instructions on how to configure your browser to manage cookie storage on your device.

In the case of third-party advertising cookies, you can also visit the following site:, offered by digital advertising professionals within the European Digital Advertising Alliance (EDAA). From the site, you can deny or accept the cookies used by advertising professionals who are members.

It is also possible to block certain third-party cookies directly via publishers:

Cookie type

Means of blocking

Analytical and performance cookies

Google Analytics

Targeted advertising cookies


The following types of cookies may be used on our websites:

Mandatory cookies

Functional cookies

Social media and advertising cookies

These cookies are needed to ensure the proper functioning of the site and cannot be disabled. They help ensure a secure connection and the basic availability of our website.

These cookies allow us to analyse site use in order to measure and optimise performance. They allow us to store your sign-in information and display the different components of our website in a more coherent way.

These cookies are used by advertising agencies such as Google and by social media sites such as LinkedIn and Facebook. Among other things, they allow pages to be shared on social media, the posting of comments, and the publication (on our site or elsewhere) of ads that reflect your centres of interest.

Our EZPublish content management system (CMS) uses CAS and PHP session cookies and the New Relic cookie for monitoring purposes (IP, response times).

These cookies are deleted at the end of the browsing session (when you log off or close your browser window)

Our EZPublish content management system (CMS) uses the XiTi cookie to measure traffic. Our service provider is AT Internet. This company stores data (IPs, date and time of access, length of the visit and pages viewed) for six months.

Our EZPublish content management system (CMS) does not use this type of cookie.

For more information about the cookies we use, contact INRA’s Data Protection Officer by email at or by post at:

24, chemin de Borde Rouge –Auzeville – CS52627
31326 Castanet Tolosan CEDEX - France

Dernière mise à jour : Mai 2018

Menu Logo Principal

Home page

Photoperiodic sensitivity in domestic female birds.

INRA Prod. Anim., 9 (1), 25-34.


INRA Station de Recherches Avicoles 37380 Nouzilly


Research works devoted to the photoperiodic sensitivity of domestic birds have been largely developed for half a century (between the thirties and the eighties) and have opened up the way to numerous applications in poultry practice. In the first part of the present paper, the main basic data concerning the perception and roles of photoperiod in birds are mentioned, namely : extraretinal (through the skull) perception of light and its consequences for the stimulating effect of different wavelengths ; the double role of photoperiod, both stimulant of reproduction on a long term basis and daily synchronizer of the endocrine events which end up in ovulation and clutch formation ; the apparently low involvement of melatonin into this mechanisms ; the notion of subjective day, underlaying the interrupted lighting programmes.

The second part of this paper is devoted to a summarized and updated presentation of the applications of these data to the laying hen, already largely exposed. The modulation of sexual precocity by manipulating daylength is still a classical component of the pullet rearing (at least outside the tropical zone). On an other hand, the sensitivity of the adult hen to daylength seems to have been reduced during the last three decades, inprobable relationship with the strong selection pressure exerted over the laying rate of this species. Some egg characteristics (such as egg-weight and eggshell thickness) can be improved by ahemeral lighting programmes longer than 24 h, or by short cycle symmetric programmes (without any main night period) which have been more used in the French context. Asymmetrical interrupted lighting programmes, keeping a main night period, can allow some productivity savings without any modification of the egg characteristics. Possible effects of these treatments on the hens’ welfare are also mentioned.

Download documents