Do extensive poultry systems really offer superior welfare?

The term 'animal welfare-friendly systems' is now in common use even in official documents, including the European Union (EU) 6th framework 'Rescape' and 'Safehouse' research projects. A survey of European consumer attitudes published last year found that 'Consumers were prepared to pay a higher price for animal products from more animal welfare-friendly systems.'

What does the term 'welfare-friendly' mean? It infers that animals kept in such systems are more comfortable, suffer less, have more freedom and are more content. But is it based on facts or perception? Whatever their opinion, can consumers actually discern whether the food they buy comes from superior systems in terms of animal welfare?

The following two examples both from extensive poultry housing systems widely perceived as being welfare-friendly cast doubt on whether these systems are actually superior to others in terms of bird welfare.

Housing systems for laying hens

European Directive 99/74/EC lays down minimum standards for the protection of laying hens. It will lead to the phasing out of conventional (battery) laying cages by 2012, whilst allowing the continuing use of enriched cages and alternative systems. Several recent and current scientific studies aim to compare the welfare friendliness of different systems of egg production. These include:

• LayWel project: welfare implications of changes in production systems for laying hens (funded by the EU).
• Comparative welfare of layers in different production systems assessed using Swedish animal welfare standards (UK Agricultural Development and Advisory Service, ADAS)
• Assessment of welfare of laying hens in current housing systems (University of Bristol, UK).

Findings from studies published to date conclude that no particular system has overall superior bird welfare. Laying hens in conventional cages are generally reckoned to have poor welfare mainly because they only express a limited behavioural repertoire. Hens have a range of behavioural needs, priorities and preferences, which are met to varying degrees in different systems.

Reviewing the Directive in 2005, the Animal Health and Welfare Panel of the European Food Safety Authority (EFSA) made several recommendations. One of these was that Efforts should be made to minimise mortality and morbidity in order to reduce the risk of poor welfare. Only those systems, in which there is expected to be low mortality, should be used.'

Mortality in free-range layer flocks

In the comparative welfare study conducted by ADAS research scientists, results from 39 selected well managed flocks of beak-trimmed hens were compared. At 14%, cumulative mean mortality was high in free-range flocks 16 to 70 weeks of age. Three of nine free-range flocks exceeded 16% mortality at 70 weeks of age, six flocks exceeded 12% and eight of the nine flocks exceeded 9%. This latter figure is the maximum acceptable mean mortality during the laying year under the criteria of the respected Swedish Animal Welfare Ordinance. Mean mortality was just 3% over the same period in furnished laying cages, a level typical of current egg industry experience.

The results require serious consideration because mortality is an important welfare indicator as hens generally suffer during the period of morbidity preceding it.

Further investigation is required into the causes of the high and variable mortality levels in free-range laying flocks, and possible remedies. Likely causes are multi-factorial, and known to include feather-pecking and cannibalism sometimes involving consequent infections, various diseases, endoparasites (e.g. worms), underweight pullets, smothering and predation.

Several of these factors are associated with daytime access to land. Ironically, some have probably been exacerbated by measures encouraging hens to leave the house, e.g. by the provision of outside shelter, shade, water and sometimes feed. Reduced fox control as the result of a national ban on hunting may also have been a factor. Mortality can be expected to become more serious if/when beak-trimming is banned, as is planned in the UK by the end of 2010.

Another aspect of free-range mortality is ‘missing' mortality, i.e. the discrepancy between the number of pullets housed less recorded losses and hens depopulated. In a detailed study of 18 flocks of intact-beaked organic free-range hens in Denmark, the average rate for missing' mortality was 3.4%. Together with the mean mortality recorded by producers of 19.1%, this produced a total over the laying year of 22.5%. The report authors commented, No clear explanation can be given for the high number of missing hens [range: 0-11.9%] but it is assumed that predators took most of them.' The researchers concluded, The results do not provide a definite answer to the question whether or not hens should be kept outside.'

Mortality in free-range flocks is a specific welfare problem that must be addressed if extensive systems of egg production are to remain in use. High and variable mortality levels cast doubt on the perception that free-range is the most animal welfare-friendly system of egg production.

This finding is not new. Mortality was a major problem during the 1930s when virtually all poultry were kept extensively. Losses over 20% were not uncommon. Causal factors then included 'fowl-sick' land, Salmonella pullorum, red and scaly leg mite, coccidiosis, worms, comb frostbite, crop binding and losses to predators.

In the past, it was thought that free-range hens might be less stressed than caged ones because those in cages may be frustrated by limitations to their behavioural repertoire. However, a recent trial indicated that similar levels of corticosterone a hormone produced in response to stress or fear have been found in eggs from free-range and caged hens.

Chart 1: Mortality in nine free-range laying flocks 

Chart 2: Average mortality in laying flocks kept in different housing systems 

Housing systems for broilers

Broiler production has been managed almost entirely in controlled environment housing for many years but niche markets for slower growing free-range and organic chickens have grown recently. Some consumers are prepared to pay substantial premiums for these products, which are perceived to be more welfare-friendly. However a specific welfare problem of intensively housed chickens has been found with much greater prevalence in extensive free range, and especially organically reared, chickens. This comes under the term, contact dermatitis and includes hock burn and foot pad dermatitis (FPD).

Foot pad dermatitis in free-range and organic broilers

European Union Broiler Directive (EU Council Directive 2007/43/EC) will put in place general measures to control and minimise the widespread incidence of FPD in standard intensively reared chickens. However, FPD is a much greater threat in free-range and organically reared chickens than in standard broilers. This was conclusively demonstrated in a large-scale study at the University of Bristol in 2006, involving almost four million birds in 359 flocks on 91 farms. They found that the mean prevalence of FPD in standard intensive broiler systems was 14.8%. However, free-range and organic flocks that had access to the outside showed significantly higher prevalence of FPD than those kept entirely indoors: 32.8% in free-range birds and 98.1% in organically reared ones. Severity of the condition varied but it was greater in extensive systems, especially organic ones.

It is accepted that FPD has important welfare implications because the lesions are probably painful, as a result of tissue trauma the degree of which will vary with lesion severity and are frequently in contact with surfaces that may increase the problem and stimulate the pain. This indicates a widespread severe welfare problem in extensive systems, which have been designed and are portrayed to reflect superior bird welfare to intensive systems. FPD lesions are not seen by consumers because feet and legs are usually removed from carcasses during processing. There is also an important association between FPD and other forms of contact dermatitis e.g. hock and breast burn.

Causal factors of FPD in chickens and growing turkeys include litter quality, litter type, drinker type, house temperature and relative humidity, bird age, rearing conditions e.g. stocking density and various aspects of feed source and composition. Whilst there is little available published information on this, it is likely that extensive chickens reared mainly in small houses with relatively large pop-holes experience wet conditions outside, especially near the pop-holes, and bring moisture into the houses on their feet. This can result in damp litter, which in combination with the chemical burning effect of ammonia from urea in the litter is a known cause of FPD. Thus, poor litter quality may cause FPD lesions on the feet of birds that do not go outside.

Requirements to reduce the incidence of FPD beyond those in the Broiler Directive should be assessed, developed and applied in extensive systems as soon as possible. There is increasing evidence that the incidence and severity of contact dermatitis may reflect several aspects of bird welfare, as well as being a direct cause of pain, and so may provide a valid assessment measure for broiler welfare. FPD scoring could be used by production companies or in accreditation schemes. This matter of reducing FPD and other forms of contact dermatitis should be of particular concern to all involved in free-range and organic chicken production and marketing, since these systems are portrayed as being welfare-friendly.

Table 1: Prevalence and severity of food pad dermatitis (FPD) in broiler chickens in different systems 

Conclusions

In its presentation to consumers, poultry welfare should be soundly based. Efforts to inform consumers and to address their concerns about animal welfare need to be at the forefront of policy and industry agendas. The examples provided here of two readily available welfare assessment measures indicate much greater problems in extensive rather than in intensive production systems.

There are other important indicators of poultry welfare that must also be taken into account, but these two should serve as a reminder that no single system is outstandingly superior in all aspects of poultry welfare. Allowing poultry outside access increases their freedom and behavioural repertoire but it is accompanied by greater risks to important aspects of their well-being.

The term 'welfare-friendly' must take all these factors into account.