Selecting hens based on their behaviour in the nest can reduce the number of floor eggs. These are the findings of a study conducted in collaboration with INRAE and published on 25 January in the scientific review Genetics Selection Evolution.
Alternative systems are becoming the most popular form of rearing in Europe and are being introduced in the rest of the world. Reducing floor eggs is one of the major problems in these systems but this behaviour is difficult to measure on an individual level. However, the development of electronic nests provides hope of a genetic improvement in the nesting behaviour of hens reared in groups. The aim of this collaboration between NOVOGEN and INRAE was to study the genetic determinism of nesting behaviour, to identify new selection criteria to reduce floor eggs.
For this study, 2000 hens of the NOVOgen Brown and NOVOgen White lines were reared together in floor pens. Their nesting behaviour was recorded at high-throughput over 40 consecutive weeks using electronic nests developed by NOVOGEN. The data collected was used to determine the exploration traits, such as the percentage of different nests used for laying eggs, or the laying duration.
We observed a marked variability in traits. In terms of exploration, 9 to 96% of nests were used depending on the hen. Between 18 and 37% of these differences proved to be of genetic origin. The hens spent between 11 minutes and 2 hours and 22 minutes in their nests for laying. 54 to 68% of differences were explained as genetic! We also estimated favourable genetic correlations between these traits and nest laying.
The results show that genetics has a moderate to strong influence on the nesting behaviour of laying hens. Focusing on this would therefore be a key way to improve nest laying in alternative rearing systems. Selecting the most inquisitive hens which spend less time in the nests is therefore a way of optimising nest occupancy and reducing floor eggs.
These traits were measured routinely in NOVOGEN floor selection systems and were integrated into selection programmes for all of the company’s lines.
Reference: Bécot L., Bédère N., Coton J., Burlot T., Le Roy P., 2023. Nest preference and laying duration traits to select against floor eggs in laying hens. Genetics Selection Evolution 55, 8.
https://doi.org/10.1186/s12711-023-00780-8
