PS/MJ/BR9718 April 2002 ENRICHED CAGES FOR EGG-LAYING HENS B R I E F I N G EU ban on the conventional battery cage The 1999 EU Hens Directive bans the conventional battery cage from 2012. The ban is well founded on the science. In their 1996 report the European Commission s Scientific Veterinary Committee (SVC) condemned the battery cage concluding that: It is clear that because of its small size and its barrenness, the battery cage as used at present has inherent severe disadvantages for the welfare of hens. (Emphasis added). Usually in the UK and the rest of the EU, 5 hens are crammed into a cage so tiny that they cannot even stretch their wings or turn around without difficulty. The SVC report established that hens have a:?? strong preference for laying their eggs in a nest and are highly motivated to perform nesting behaviour?? strong preference for a littered floor both for pecking and scratching and for dustbathing?? preference to perch, especially at night. None of these natural behaviours are possible in the battery cage. In addition, due to lack of movement, battery hens have such brittle bones that many suffer from broken bones by the time they come to be slaughtered. In the light of the above, the EU ban on the battery cage is extremely welcome. Disappointingly, however, the EU Hens Directive allows enriched cages to be used. Enriched cages Under the Directive, enriched cages must be at least 45 cm. high and must provide each hen with at least 750 cm² of space; 600 cm² of this must be usable area the other 150 cm² is for a nest-box. The cage must also contain litter, perches and claw-shortening devices.
These apparent improvements on the conventional cage are, however, largely illusory. Enriched cages provide:?? too little space to enable hens to perform many basic movements such as stretching their wings, flapping their wings and turning without difficulty?? too little height to allow hens to perform a proper range of natural head movements?? facilities that are so minimalist that hens cannot dust-bathe, lay their eggs in a nest or perch in any way that is meaningful for the birds. Accordingly, Compassion in World Farming (CIWF) believes that enriched cages should be prohibited as they provide no significant or worthwhile welfare benefits as compared with conventional battery cages. It would be extremely disappointing if the Hens Directive merely led to producers switching from conventional cages to enriched cages rather than to good perchery and free-range systems. Indeed, Germany has prohibited enriched cages from 2012. CIWF urges the UK and the rest of the EU to follow Germany s lead. (Germany has also banned conventional cages from 2007, five years earlier than required by the EU Directive). CIWF s detailed concerns about enriched cages are as follows: Space A study by Dawkins & Hardie (1989) looked at the area used by hens in performing certain behaviours. Their results are shown in the following table: Behaviour Area used (cm²) Mean Range Standing 475 428 592 Ground scratching 856 655 1217 Turning 1272 978 1626 Wing stretching 893 660 1476 Wing flapping 1876 1085 2606 Feather ruffling 873 609 1362 Preening 1151 800 1977 This study shows that the average space used by hens to perform certain basic behaviours is between 475 cm² and 1876 cm², although hens can use as much as 2606 cm² at the top end of 2
the range. Almost all normal hen behaviours require more space than the 600 cm² of usable space per bird required for enriched cages by the EU Hens Directive. It is important to note that the behaviours included in the above table do not include a number of activities important to hens such as walking, running, fluttering and flying, for which even more space is needed. Conclusion: It is clear that the 600 cm² of usable space per bird required for enriched cages by the Hens Directive almost completely fails to allow sufficient space for hens to perform a range of basic, important behaviours. Height Under the EU Hens Directive, enriched cages must have a height of at least 45 cm. over the 600 cm² of usable area per bird. CIWF believes that a height of 45 cm. is inadequate. A greater height is necessary to allow hens properly to perform behaviours such as head stretching and body shaking which lead to stronger wing bones. Research by Dawkins (1985) concluded that any cage lower than 46 cm. at the front and 37 cm. at the rear was shunned by the hens. This study also shows that hens will use up to 56 cm. of cage height if given the opportunity. As hens may spend a significant proportion of their time on the perches, cage height should be measured not from the floor, but from the perch. Perches in cages are normally set at least 7 cm. above floor level to allow eggs to roll under them. As we have seen, research shows that hens should be given a cage height of at least 46 cm. If measured from the perch, this means that hens should have a cage height of at least 53 cm. (46 cm. plus 7 cm.). Moreover, research also shows that hens will use up to 56 cm. of height if given the opportunity. Here too, the figure should be measured not from the cage floor but from the perch, meaning that hens should preferably be given a minimum cage height of 63 cm. (56 cm. plus 7 cm.). Conclusion The minimum cage height should be no less than 53 cm., and preferably 63 cm., figures significantly higher than the 45 cm. required by the EU Hens Directive. 3
Nests Enriched cage designs tend to include one nest box in each cage. CIWF fears that a nest box placed within the restricted confines of an enriched cage will fail to properly fulfil the hens behavioural need to lay their eggs in a nest and to perform nesting behaviour. Hens are most likely to lay their eggs around the start of the daylight period. Competition for the nest box at this particular period is likely to cause aggression among cagemates. Under natural conditions, the hen stays at the nest site for about 1-2 hours during egg-laying. Disturbances within the cramped confines of the enriched cage are likely to lead to hens spending much less time at the nest site than they would like to. Dust-bathing Most enriched cages have a litter area or dustbath sited on top of the nest area, which is positioned width-ways at one end of the cage. Access to the litter area is sometimes restricted in enriched cages to certain times of the day to prevent hens laying their eggs in the litter. Research has found that only 26.7% of dust-bathing bouts in enriched cages occur in the dustbath even when access is unrestricted. Where access is restricted, this figure falls to 8.3% (Lindberg & Nicol, 1997). Most dust-bathing in enriched cages occurs as abnormal sham or vacuum dust-bathing on the wire floor an activity that fails to satisfy the hens behavioural needs. In natural conditions, hens will dust-bathe once every two days for about 20-30 minutes. In enriched cages, however, dust-bathing tends to be abnormally short and incomplete. Dutch researchers report that in enriched cages dustbaths with a normal duration were hardly ever seen (van Niekerk & Reuvekamp, 2000). Similarly, research has found that dustbathing in enriched cages was unsatisfying and the dustbath motivation remained high and that the hens were frustrated (van Rooijen, 1998). Van Niekerk & Reuvekamp (2000) concluded that due to practical reasons it is not possible to supply a thick layer of litter in cages and therefore dustbathing in cages will never be optimal. Conclusion: Too little litter and too little physical space, together with disturbance from cagemates, leads to dustbathing in cages often being abnormally short and incomplete and failing to satisfy the hens strong behavioural need to dustbathe. 4
Perches The Hens Directive requires only 45 cm. of cage height. With so little height available, perches are likely to be placed just a few centimetres (about 7 cm.) above the floor. Scientific evidence suggests that low perches in cages are perceived, not as a perch, but as a different quality of floor (Tauson, 1984). These low perches provide a means to escape the discomfort of the sloping wire floor used in cages, but do not meaningfully fulfil the hens perching needs. Conclusion: Perches in enriched cages are unable to satisfy the hens need for a raised perch for roosting. Overall conclusion: Enriched cages provide too little space and too little height to enable hens to perform many important basic movements such as wing-stretching, wing-flapping and turning without difficulty. Moreover, they do not allow hens properly to satisfy their behavioural needs to lay their eggs in a nest, dustbathe, peck and scratch at the ground and perch. Accordingly, CIWF believes that the use of enriched cages should be prohibited. High welfare alternatives CIWF believes that, as the conventional cage is phased out prior to its prohibition in 2012, the industry should switch not to enriched cages but to percheries and free-range systems which, if well-managed and well-designed, have the potential for high welfare. Key factors in a good free-range system include the following: a) The outdoor stocking density should not exceed 1,000 hens per hectare in the interests of welfare, and to avoid damage to the vegetation and to prevent nitrogen and phosphorus contamination of the range. b) Paddocks should be rotated to prevent parasitic infections. However, in order to ensure that this rotation does not lead to hens having too little space, each hen should have access, at any one time, to at least 4 m² of outdoor range. c) Hens mostly only use outdoor space which is within 100 m. of the henhouse. Areas beyond 150 m. are hardly used at all. Accordingly, outdoor space should all be located within a maximum of 150 m. from the henhouse. d) The group size should not exceed 500 hens, and indeed preferably should not exceed 250. 5
De-beaking Opponents of percheries and free-range misleadingly argue that de-beaking is necessary in such systems to prevent feather-pecking and cannibalism. However, both scientific research and practical experience show that these behaviours can be addressed without resorting to the painful mutilation of de-beaking. Key factors involved in preventing feather-pecking and cannibalism include:?? The provision of ample, high quality litter. A number of scientific studies show that when hens are prevented from (i) pecking and scratching at the ground and (ii) dust-bathing, they may re-direct these behaviours into pecking the feathers of other hens. The provision of good quality and extensive litter enables hens to engage in pecking and scratching and dust-bathing, thereby reducing feather-pecking.?? Avoiding overcrowding.?? Keeping group sizes relatively small.?? Using strains of hens which are less prone to feather-pecking. PETER STEVENSON Political and Legal Director Acknowledgement: Much of this briefing is closely based on a report prepared for Compassion in World Farming by Philip Lymbery, Animal Welfare Consultant. 6