What are the risks when hens lay their eggs on the floor?

Hens usually prefer to lay their eggs in nests but it is not unusual for some eggs to be laid on the floor of the hen house or on the ground and in some cases the incidence of floor eggs can be quite high. A new study aims to identify the most important risk factors for floor laying in hens and explore whether any of the methods that are currently employed by farmers to deal with the problem actually work.

The survey, led by academics in the University of Bristol's School of Veterinary Sciences, hopes to find out from egg producing farmers how widespread the floor egg problem is in UK farms and to gather information about what factors might affect the issue.

The researchers would particularly like to understand if there is any association between the severity of the floor eggs issue and areas, such as:

• Different breeds of hens, i.e. whether there is a genetic influence.
• The level and type of intervention by the farmer to reduce the number of floor eggs.
• General flock management practices, such as diet and husbandry.
• Housing conditions.
• The age of hens when they come into lay and peak in their production.

Margarita Maltseva-Williams, a postgraduate in Clinical Veterinary Science, who is leading the study, said: "Very little research has been done on why some hens lay their eggs on the floor of the hen house or on the ground and as far as I am aware this is the first survey to explore the issue on commercials farms.

"Floor laying in hens can be a real problem for farmers and we hope the findings from our study will help them and their flocks in the future."

Floor eggs can have increased risk of being soiled by manure or being cracked. They may also not be found quickly by the egg collector. Consequently, floor eggs are more likely to be contaminated by bacteria, which reduces their shelf life and makes them more likely to carry food-borne pathogens. Broken floor eggs may also trigger egg eating by birds in the flock, which can be hard to stop once it starts.