Alternatives to Battery Cages

Free range

Free range was the traditional way of keeping small flocks of hens on mixed farms. Larger flocks can be successfully managed, but require enough land and good stockmanship.

Free range producers associations in Victoria and New South Wales have set standards for free range egg production, which include:

In larger groups of hens, aggression can be a problem. Therefore it is especially important to choose the right strain of hen. As Queensland free range producers are advised: " By choosing quieter, more docile strains potential outbreaks of cannibalism are significantly reduced ." (1)

Ian Littleton in NSW has for many years been researching efficient management of free range hens, especially in conjunction with other farming such as sheep grazing. He uses portable sheds for 600 hens, mounted on skids for easy towing from one paddock to another (2). The sheds have perches, mesh floors for droppings to fall straight through, nest boxes, and dust bathing boxes with sand and dolomite to control ectoparasites. Paddocks have electric fences to keep out predators. The sheds are regularly moved to make sure hens have access to good quality pasture. To this end, Littleton reduced the stocking density to 750 hens/hectare. When the hens are moved on, the paddock is irrigated and sheep graze the excellent grass growing on the poultry manure.

Littleton commented (3): " We want to demonstrate that you can run free range hens and maintain pasture so that the birds are healthy and are not being subjected to parasitic infections which you can get on muddy runs ."

This system of small movable sheds is being used successfully by free range farmers near Bendigo in Victoria. There are 10 sheds, each housing 100 hens, and containing food, water, laying boxes and perches (4).

Alternatively, hens can be kept in permanent sheds, with the surrounding area divided into different paddocks, so that hens can be released into one paddock at a time.

Other important factors in system design include:

However, the most important factors are selecting the right strain of hen for the conditions to minimise aggression, and having enough land to move hens regularly onto fresh pasture to avoid a build-up of disease and parasites. Then hens can enjoy the benefits of the system, including freedom of movement leading to strong bones, opportunity to express all their natural behaviour, and good air quality.

Deep litter or barn system

RSPCA Australia has introduced a system of certification for eggs that meet their standards. Although the standards don't specify that hens must be kept in sheds on litter, the eggs that have been certified to date are all produced in this way.

The RSPCA guarantee states: " These eggs are produced to RSPCA standards as the hens are maintained according to RSPCA requirements. The hens have litter in which to dust bathe, space to flap wings, stretch and socialise, nests in which to lay their eggs, and adequate perch space. They have constant access to fresh water and feed and are protected from the elements and predators ."

There must be no more than 5 hens/sqm of shed space, with a maximum group size of 5000. At least one third of the barn must be covered in litter, and there must be adequate nest box and perch space for all hens. Debeaking is limited to cutting the hook on the end of the top mandible in the first week of life - any more severe debeaking may be done only on veterinary advice. For more details about the standards, go to RSPCA Certification Standards for Eggs.

Australia's largest egg producer, Pace Farms in NSW, has become involved in the RSPCA scheme and expects to produce 1.6 million dozen eggs a year. Nest boxes are designed so that eggs roll out onto a conveyor belt for easy collection. The nest boxes are well accepted by the hens, and only about 3-4% of eggs are laid on the floor. According to the managing director, productivity in the system is good, and only about 5% below cages (5).

As on free range, deep litter systems offer greater freedom of movement and opportunities to express natural behaviours. Temperature and weather control are easier than on free range, but keeping up high air quality is more difficult. With the higher stocking density than on free range, attention has to be paid to keeping litter clean and avoiding manure and ammonia build-up. As for free range, it is essential to choose the right strain of bird to minimise aggression.

Percheries, aviaries and modified cages

European countries have developed various systems for housing hens indoors without battery cages. For example, Danish researchers developed the Hans Kier system, where 80% of the floor is wire mesh to allow droppings to fall through, but there are many perches above the wire for birds to stand on. The remaining 20% of the floor is covered in sand to allow dust bathing. Nest boxes lined with cut straw are also provided. A commercial trial of this system achieved a high level of productivity, 289 eggs/hen over a 52 week period (6).

UK researchers in particular have investigated percheries as an alternative to cages. The Michie perchery has been particularly successful. In this design, perches at different levels are attached to an A-frame standing over wire mesh to allow dropping to fall through. Beside the perches the floor is covered with litter, and nest boxes are provided. Because hens use the vertical space as well as the horizontal space across the floor, stocking densities are higher than on deep litter, with up to 25 hens/sqm of floor space.

Several studies have found similar egg production and mortality in these percheries as in cages, as shown in the table below:

Cages

Perchery

Time

Egg production/hen

290

276

52 weeks (7)

285

275

52 weeks (8)

137

133

24 weeks (9)

Mortality (%)

5

7

52 weeks (7)

5.4

4.6

52 weeks (8)

2.5

1.4

24 weeks (9)



When Switzerland effectively banned standard battery cages, the aviary became the most widely used system. There are several different designs, but in all part of the floor is covered with litter for scratching and pecking, there are wire platforms at several levels with food and water, perches on the top level, and nest boxes adjacent to the wire platforms that hens fly to from the platforms. As in percheries, up to 25 hens can be kept per square metre of floor space.

Investigations by Swiss researchers over 5 years have shown that the aviary is a viable system, with a cost increase of only 9.5% over cages. The table below compares productivity and mortality (10):


Cages

Aviary

%eggs/yield/bird/day%

79.8

77.3

Mortality (%)

5.2%

8.0%


Supporters of battery cages like to claim that since the ban on such cages in Switzerland the number of cheaper imported eggs (from caged hens) has increased. In fact, this claim is not true. Since the ban, egg production in Switzerland has increased, the number of imported eggs has decreased, and the consumption of locally produced eggs has increased. The major supermarket chains, Migros and COOP, now stock only eggs from non-caged hens (11).

In the Netherlands, another aviary design, the Tiered Wire Floor (TWF) system has been trialed extensively. In one study over a 40 week period, it produced 238.4 eggs/hen compared to 238.7 from hens in cages, with a mortality of 3.8% in TWF and 2.6% in cages (12).

Researchers in the UK have investigated ways of modifying cages to allow hens to express their normal behaviours. The Edinburgh modified cage provides more space than a conventional battery cage, has a perch, a dust bathing box and s laying nest attached to the side of the cage. Like battery cages, they hold around 4 hens.

The modified cage allows a wider variety of behaviours than the battery cage. It has the advantage of small groups and low levels of aggression. Hens have less feather, foot and claw damage than in standard cages. However, there still isn't enough room for large movements like wing flapping, and as a result hens still have weak bones.

Hens in modified cages produce a similar number of eggs to those in battery cages. Production costs are 5-10% higher because of the greater space allowance/hen (13). Modified cages could comply with the European Union requirements after 2012, that is, at least 750sqcm of space per hen, a nest, litter and perches. However it remains to be seen whether modified cages are taken up commercially.

References

  1. Anon (1991-2), "Qld forms free range association", Milne's Poultry Digest Dec/Jan (12-13) (12-13)

  2. McErlane B (1992), "Free range project expanded", Milne's Poultry Digest , Oct/Nov (19)

  3. McErlane B, (1991-2), "Project tests viability of free range hens", Milne's Poultry Digest Dec/Jan (6,9)

  4. Parkinson M (1997), "Mobile sheds work well", Milne's Poultry Digest , Feb (17)

  5. McErlane B (1997), "Pace offers consumers a choice with RSPCA-endorsed Liberty eggs", Milne's Poultry Digest , October (8-9)

  6. Norgaard-Nielsen G (1989), "Alternative systems in Scandinavia", in A Kuit et al, Alternative improved housing systems for poultry , Proceedings of CEC Seminar held at Beekbergen, the Netherlands

  7. Tucker S (1991), "Development of systems for improved welfare - poultry management", in S Carruthers (ed), Farm animals: it pays to be humane , Papers presented at a conference organised by the Centre for Agricultural Strategy, London

  8. Keeling L (1989), "Alternative housing systems for laying hens in Great Britain", in A Kuit et al, Alternative improved housing systems for poultry , Proceedings of CEC Seminar held at Beekbergen, the Netherlands

  9. McLean K (1986), "A comparison of the welfare of laying hens in battery cages and in a perchery", Research and Development in Agriculture , vol 3 (93-98)

  10. Amgarten M & Meierhans D (1992), "Vergleichende Untersuchung der Wirtschaftlichkeit verschiedener Haltungssysteme fuer Legehennen in der Praxis and an der SGS," Bericht ueber die Jahre (1986-1990), Schweizerische Gefluegel Schule, Zollikofen

  11. Animals Australia (1999), "Review of Layer Housing in Australia", submission to the SCARM

  12. Ehlhardt D et al, "Alternative systems in the Netherlands", in in A Kuit et al, Alternative improved housing systems for poultry , Proceedings of CEC Seminar held at Beekbergen, the Netherlands

  13. Robertson E et al, (1989), "Modified cages for laying hens: a pilot trial", Research and Development in Agriculture, vol 6 (107-114)