There is a long wish list where the various characteristics of layers are concerned. Regardless of varying environmental effects and market demands, laying hen farmers expect a high number of eggs per hen to secure their sources of income. Moreover, in non-cage systems, it is of big importance that layers show a good nest acceptance to prevent floor eggs. This requires a certain amount of activity, which, on the other hand, should not be too much as this will result in the observance of a relationship between intensified activity and atypical behaviour patterns.

From the breeder’s point of view, these wishes can only be considered if an applicable data recording system exists. Ideally, this has to be a highly accurate hen-specific observation of distinctive traits that can be practically applied on a certain number of birds. Direct observations in non-cage systems are too labourintensive and time consuming and can therefore be ruled out. Instead, automatic data recording systems that capture data information from each individual hen are desired.

In groups of several hundred layers, Lohmann layers are tested with different electronic data systems, hen-specifically. Since 2004, a few years after the first prototype of an “automatic nest” was tested, Lohmann Tierzucht had been testing their layers in 48 Weihenstephan Funnel Nest Boxes. Since then, the technicians have fine-tuned the mechanism, electronic and software. Four years later, 72 modified Weihenstephan Funnel nest boxes were available to capture the data of individual egg numbers of each single hen in a group housing system with an accuracy of 97 %. Each laid egg can be assigned to the respective hen at the end of the production day. This allocation allows hen-specific egg quality measurements for breeding purposes too. Aside from the exact egg numbers of Lohmann layers in group housing, it is possible to capture data on other important traits such as egg weight, eggshell stability and other egg quality related traits for every single hen.

Furthermore, we always get new and relevant information about the nesting behaviour of individual hens which is of importance for nest acceptance and the required nest space in a group housing system. The relationship between the laying performance and the free-range behaviour of individual birds is of special interest. Presently, this question can only be answered with data that is captured on Lohmann layers at the experimental station of the Technical University in Munich. An adjacent winter garden that can be reached by the layers via electronic pop holes, records the frequency of free-range passages and the time spent outside for every hen.

With the use of single nest boxes (Weihenstephan Funnel Nest Box) and Single Pop Holes, there are constant requests for more practical relevance in terms of the design of commercial nests and pop holes. The result is a second test compart

Figure 1: Hen specific performance testing in Weihenstephan Funnel Nest Boxes and Single Pop Holes





Figure 2: Hen specific performance testing in Family Nests and Wide Electronic Pop Holes



ment with modified family nests and Wide Electronic Pop Holes that can be used by several hens at the very same time. With the aid of high frequency transponders, each single hen can be recorded individually. With this technology, we are getting new information from the nesting and free-range behaviour of Lohmann layers on a daily basis

Differences in the duration of nest occupancy are shown between brown and white layers. In general, every laying hen visits the Weihenstephan Funnel Nest Box once per day, whereas the same layer is occupying the family nest several times during the day. Several short visits are often followed by one longer nest visit. Therefore, the average time of nest occupancy is around 30 minutes per day for brown layers and just over an hour for white layers. In a family nest, a single nest visit is slightly shorter as compared to a visit in the Weihenstephan Funnel Nest Box, when the hen is laying an egg. Nest visits without oviposition are mainly observed at the beginning of production and do not take longer than nest visits with oviposition (table 1). As soon as the hen enters her continuous laying cycle, in which she lays on a very high production level, she will go into the Weihenstephan Funnel Nest Box to lay an egg only once per day. Similar to the results from single and family nests, there are differences observed between the usage of Single and Wide Electronic Pop Holes.

If the adjacent winter garden can be reached via Wide Electronic Pop Holes, nearly every layer will visit the outside run at least once per day. Compared to the Single Pop Hole, a maximum of 30 % of the layers is using the winter garden during the observation period. An important statement on figure 3 is that the layers never visit the winter garden at the same time. During the day, at least 50 % of the hens are resting inside. At midday, an increased number of layers will visit the winter garden, an observation which is similar for both pop hole designs. With the use of Single Pop Holes, a maximum of 10 % of the layers from one flock will use the winter garden at the same time.

The information which are captured from these systems such as hen-specific egg numbers and their egg quality values as well as the nest and free-range behaviour can be used for breeding purposes. Pedigree layers that are tested next to their single cage performances to such

Table1: Average values for the duration of nest occupancy in single and family nests according to brown and white layers



Figure 3: Free-range usage of layers with different Pop Hole designs



a high extent in group housing systems can be selected in terms of an improved nest acceptance and a minimum of floor eggs. One of the main advantages is the knowledge about the individual laying performance of the hens and their activities. Only with the knowledge of this relationship, the breeder has a tool to consider these selection traits when choosing the qualified hens for the next generation

Dr. Wiebke Icken

Table 2: An overview about the hen specific performance testing on Lohmann layers in group housing systems