Which system offers the best welfare?

The welfare benefits of different types of housing for layers have long been debated within the egg industry.

A major study by ADAS now hopes to reveal some of the comparative advantages associated with various egg production systems.

The British Egg Industry Council which is providing the bulk of the funding for the project says the aim is to establish the relative welfare of laying hens kept in a variety of intensive and extensive egg production systems currently used in Europe.

The BEIC believes that gathering such information is important in light of the impending review of the EU's Welfare Directive.

The study commenced in 2004 and was due to conclude in April this year but has now been extended for a further year to include more free range flocks and birds kept in furnished—or enriched—cages.

By the time the trial finishes a total of 39 flocks will have been examined, representing birds housed in conventional and enriched cages, free range and barn systems. The 10 free range flocks being studied include those housed in both static and mobile buildings along with an aviary-type system located in the Netherlands.

The study takes into account flock production levels, physical condition of the birds and an assessment of environmental conditions. The protocol requires that participating farms keep detailed records including a diary of any factors "that may affect the study or the well being of the birds". A log of daily house temperatures will be kept along with details of water and feed intake during the length of the study which aims to follow each flock from 16 to 72 weeks of age.

Bodyweights will be recorded regularly as will mortality levels and details of daily egg numbers, including the level of seconds. Floor egg numbers must also be taken into account.

When it comes to the physical condition of the birds, this is ascertained by an inspection of 30 birds selected randomly from each flock at 35 weeks and again at 60 weeks.

ADAS staff have been specially trained to individually examine the birds and score them according to respected welfare standards devised by the Swedish board of agriculture. This procedure includes giving the birds a feather score; assessing them for peck wounds both to the comb and back region; checking for keel bone damage; and examining feet for evidence of bumblefoot and broken claws.

At the time of this visit ADAS staff will monitor environmental conditions, including measuring the house atmosphere for ammonia and CO2 as well as dust levels. Relative humidity inside and outside the building will also be recorded.

Early results from the study indicate, not surprisingly, that feed usage in cage systems—both conventional and enriched—is lower than in alternative systems, despite bodyweight and egg production being higher in cages.

All of the flocks studied so far, says ADAS research scientist Becky Croxall, have met the Swedish welfare standards in terms of rear and back wounds, feather hygiene score and broken claws. But the interim results suggest that enriched cages are the most favourable and alternative systems the least favourable when it comes to feather cover over the back and wing areas; comb wounds, keel bone damage and bumblefoot.

ADAS does stress, however, that insufficient data has yet been collected to draw firm conclusions, with information from only two of the free range flocks included in the interim results.

For more information on Free Range visit www.bfrepa.co.uk