Alternative management systems are gaining in importance worldwide, and primary breeders are challenged to select hens best adapted to these conditions. Use of the recently developed Weihenstephan funnel nest box system for several flocks of pedigree brown-egg layers enabled Lohmann Tierzucht to study individual egg production records under conditions of floor management. In contrast to data from group cages, they were able to determine the exact oviposition time for each hen and study the laying pattern over several weeks, which is related to the total egg production. High peak rate of lay and the change to non-cage systems in Europe are good reasons to look for innovative selection criteria. Variation in oviposition time and the interval between two laid eggs are of interest in this connection.

The time of oviposition is influenced by different factors and varies from hen to hen within a flock. Most hens require slightly more than 24 hours for the production of an egg with good shell quality, but time intervals of less than 24 hours between two eggs are not unusual.

One Egg Every 24 Hours

Hens which need more than 24 hours and 15 minutes until the next oviposition tend to have a lower egg production than hens which lay one egg every day at the same time.

So-called 'turbo hens' may produce two eggs with normal shell within less than 24 hours but subsequently skip two or more days. Hens with regular intervals between ovipositions of 24 hours to 24 hours and 15 minutes have the best annual production. Such information is not only interesting for behavioural scientists. It is also useful, for example, for flock management to optimise nest capacities in alternative systems.

Light Determines Oviposition

As already shown in many previous studies, the time of oviposition is definitively determined by day-light in open houses and by the lighting programme in closed houses. The brown-egg layers tested started laying about one hour after the lights were turned on. Most of the eggs, however, were laid from about four hours after lighting.

Since most hens need a bit more than 24 hours for the production of an egg, the day time of lay will gradually become later during the course of a clutch.

During the first half of the production period, a clutch comprises mostly 11 to 13 eggs, followed by a pause of one or sometimes two days. The next oviposition after the pause is again determined by lighting programme. The main oviposition time for the brown-egg layers tested was four to five hours after start of lighting.

Hens Are Flexible

To some extent, the hens can postpone oviposition if their preferred nest or all nests are occupied, which is then seen as a deviation from the typical individual pattern of lay. Good nest acceptance combined with flexible time interval between ovipositions are desirable characteristics to minimise floor eggs. To maximise total egg production, deviations from a 24-hour time interval should not become too large.

For breeding purposes, the relation of these new characteristics to the main selection criteria – total number of saleable eggs and egg quality – is important. Preliminary results indicate that a short interval between ovipositions during the first half of the laying period is positively correlated with total annual production. More data need to be collected and analysed to substantiate the preliminary results.

Detailed Data Collection

The only practical solution available until now is the Weihenstephan funnel nest box system – individual nest boxes with an antenna integrated in the floor. Each hen is marked individually with a transponder. When a hen enters a nest, the transponder is automatically read. This information is transferred to a computer with special software to keep track of all 'nest visits'.

An egg collection tube is attached to the nest, into which the egg rolls over an egg seesaw, and the time of oviposition is recorded. A combination of the registered data – about which hen is in the nest box at a specific time, when the egg was laid and the sequence of eggs in the collecting tube – make it possible to calculate traits like the time interval, or measure the egg quality traits for a particular hen in a floor housing system, which could be used for genetic analysis.

Seventy-two units of the Weihenstephan funnel nest box are installed at the experimental station Thalhausen of the Technical University Munich. Lohmann Tierzucht is testing different lines in this unit and is beginning to use the information in the breeding programme.

Further Literature

Icken W., S. Thurner, D. Cavero, M. Schmutz, G. Wendl, R. Preisinger. 2009. Analysis of the nesting behaviour from laying hens in a floor system. Archiv für Geflügelkunde; 73: 2.
Icken W., S. Thurner, D. Cavero, M. Schmutz, G. Wendl, R. Preisinger. 2009. Genetic analysis of the laying pattern in floor management in terms of new performance parameters for breeding. Archiv Tierzucht, 2/09.
Icken W., D. Cavero, M. Schmutz, S. Thurner, G. Wendl und R. Preisinger. 2008. Analysis of the time interval within laying sequences in a transponder nest. World's Poultry Science Journal, 64: supplement 2, 231.

Further Reading

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December 2009