Defra project code: AW1301

Defra project title: The effects of the application of bits and spectacles in game birds

Contractor organisation: Game Conservancy Trust

Total project costs: £341,362.00

Project start date: 01 June 2005

Project end date: 01 December 2007

Executive summary

Like chickens and other poultry, pheasants are prone to feather pecking and cannibalism while kept in captivity. These behaviours can quickly lead to poor feather and skin condition. To prevent feather pecking in pheasant poults during rearing, game farmers often fit small plastic bits into their beaks. These prevent birds from fully closing their beaks and therefore grasping and pulling feathers from another bird. To prevent feather-pecking and egg-eating in laying pens, pheasants are fitted with spectacles. The devices reduce the ability of birds to perform these behaviours by blocking their forward vision. Despite their widespread use, the effect of these anti-feather pecking devices on the welfare of pheasants has received little attention. The aim of this study was, therefore, to examine the effects of the application of bits and spectacles on the physiological condition and behaviour of pheasants on game farms across England and Wales.

Data for the bitting and spectacle studies were collected from game farms across England and Wales between 2005 and 2007. For each study, two identical pens on each game farm were randomly allocated a treatment, with or without bits or spectacles. Management was according to normal practice on each farm and was identical for each treatment apart from the use of bits or spectacles. In both studies the body, feather and skin condition of pheasants in each treatment pen were assessed. Any abnormalities of the bill or nostrils and signs of disease were also noted. While in the bitting study pheasants were assessed weekly, the laying birds were only examined before and after the laying season in order to minimize disturbance. The behaviour of pheasants was also assessed weekly in both studies. In both studies, game farmers were required to keep detailed records of housing, feed usage, medications and treatments, mortality and unusual events. Egg collections were also recorded in the spectacle study.

In laying hens, spectacles reduced acts of bird on bird pecking but increased incidences of head scratching and shaking. In laying systems where multiple cocks were kept with hens, spectacles reduced feather damage in hens and also incidences of skin damage in both hens and cocks. The Body Mass Index of pheasants in laying pens was not affected by the fitting of spectacles. Incidences of bill and nostril damage were higher in spectacled than non-spectacled hens. Egg collection, egg weights, feed usage and mortality rates did not differ between spectacled and non-spectacled birds.

Similarly to spectacles, bits reduced acts of bird-on-bird pecking but increased incidences of head shaking and scratching. In all weeks after bitting, the feather condition of non-bitted pheasants was poorer than those fitted with bits. Incidences of skin damage were also more frequent in the non-bitted pens. On some game farms, the feather and skin condition of the non-bitted pheasants rapidly deteriorated during the trials and it was judged to bit these birds to prevent further damage. The Body Mass Index of pheasants in the bitted and non-bitted pens did not differ in any week. Bits caused nostril- inflammation and bill deformities in some birds, particularly after 7 weeks of age. In weeks 4 and 5 after bitting, corticosterone levels were higher in the faeces of non-bitted pheasants than bitted birds. Feed usage and mortality rates did not differ between bitted and non-bitted birds.

The results of this study suggest that bits and spectacles can be used to prevent welfare problems caused by feather pecking and cannibalism. A change in the design of spectacles and the fitting of larger bits to pheasant poults over 7 weeks old may reduce bill and nares damage caused by these anti-feather pecking devices. Game farmers should, however, give consideration to reducing feather pecking and cannibalism before they take root. Factors identified in the poultry industry as being stimuli for feather pecking should be further examined in relation to feather pecking in pheasants.


Project report to Defra

Scientific objectives as laid out in original contract:

  1. Identify suitable farms for both the bitting work and the work on spectacles.
  2. Set up a suitable working protocol within the main protocol for each farm to allow the farms to cooperate.
  3. Collect data comparing bitted birds with unbitted birds over two seasons.
  4. Collect data comparing birds fitted with spectacles to those without spectacles fitted (2006 only).
  5. Analyse data from each group
  6. Collate results and report the findings in final report.
  7. Validation of the faecal corticosterone technique for use in game birds.

With the exception of the objective number 7 where the work is ongoing all the other objectives have been met. The work of faecal corticosterone is underway, all samples have been collected and are currently in the laboratory being analysed. As soon as these results have been obtained and the data reviewed a supplement to this report will be issued.

1.0 Introduction

Approximately 35 million ring-necked pheasants, Phasianus colchicus, are released in Great Britain each year to supplement stocks for shooting (PACEC 2006). Pheasants are either reared by gamekeepers on the shooting estates on which they are released or by commercial game farms that supply birds to multiple estates. Although game farms often rear greater numbers of birds per annum compared to ‘on estate’ rearing practices, the rearing methods used are similar in both situations.

During the laying season, between March and June, pheasants are either placed in pens in harems or flocks. In the harem laying system, a single cock is kept with a group of approximately eight hens whereas in the flock system multiple cocks and their hens are kept together in the same ratio. Taken from over-wintered flocks or caught on local shooting estates in January, laying hens are placed in their pens in February and March. They remain in these pens until they are released onto estates in June and July.

Eggs collected from laying flocks are hatched in mechanical incubators. These chicks are then reared to 6-7 weeks of age in pens, which often consist of a ‘brooder’, ‘shelter’ and ‘run’. After hatching, pheasant chicks are initially housed in temperature-controlled ‘brooder’ houses. These may be a single hut on a rearing field or multiple separated areas within a large farm building. Then, within the first two weeks, the chicks are also given access to a shelter that provides protection from the elements but is unheated. Finally, at approximately three weeks, the pheasants are also allowed access to an outside run. The age at which chicks are allowed access to the run depends upon various factors including chick fitness, weather conditions and the rearing system used. At between 6-7 weeks old the pheasant poults are then taken from the rearing pens and released into large open pens in woodland on shooting estates.

Pheasants and other poultry kept in captivity are prone to feather pecking and cannibalism (Beer and Jenkinson 1982, Swarbrick 1985, Huber-Eicher and Sebö 2001). In addition to reducing the condition of a birds’ plumage, feather pecking can also create exposed areas of skin that may then also be pecked causing wounds (Bilčík and Keeling 1999). Feather pecking and cannibalism can therefore have an adverse effect on pheasant welfare (Swarbrick 1985). In laying chickens, Gallus gallus domesticus, the degree of plumage damage and cannibalism is influenced by various factors including stocking density, flock size, light intensity, diet, bedding material and genetics (Ambrosen and Petersen 1997, Bilčík and Keeling 1999, Kjaer and Vestergaard 1999, Kjaer and Sørensen 2002). Such factors may also influence feather pecking and/ or cannibalism in pheasants in both laying and rearing pens (Woodward et al. 1977, Cain et al. 1984, Kjaer 1997, Kjaer 2004).

Although beak trimming is often used to manage feather pecking in laying chickens, it is viewed as an unsatisfactory solution to the problem in pheasants as it may hamper foraging when the birds are released into the wild (Swarbrick 1985). In addition, beak trimming may cause possible welfare issues (Duncan et al. 1989, Gentle et al. 1990). To reduce feather pecking and egg eating in laying pens, plastic devices known as spectacles are fitted onto the beak of the birds (Plate 1). These mask the birds’ forward vision and are attached to the beak by clipping into the nostrils without piercing the septum. Spectacles are fitted to the birds when they are placed in the laying pens and removed just prior to being released into the wild. To prevent feather pecking in pheasant poults, most rearing facilities fit small plastic bits into the beak at approximately 3 weeks of age (Plate 2). These prevent birds from fully closing their beaks and therefore grasping and pulling feathers from another bird. Due to time constraints and to ensure feather pecking does not begin, many game farmers adopt a proactive stance and routinely bit their birds at a set age rather than waiting until feather pecking is observed. The bits are removed just prior to the birds being released into the wild.

Plate 1. A plastic spectacle fitted to a hen pheasant.

Plate 2. A plastic bit fitted to a pheasant poult.

Despite their widespread use, the effect of these anti-feather pecking devices on the welfare of pheasants has received little attention. Although Swarbrick (1985) suggested that bits might cause welfare issues, including increased mortality, no studies have specifically examined their effect on the behaviour or physiological condition of pheasants. The aim of this study was therefore, to examine the effects of the application of spectacles and bits on the physiological condition and behaviour of pheasants on game farms across England and Wales.

2.0 Methods

2.1 Spectacle study

2.1.1 Study sites

In 2006 and 2007, data were collected from 11 (11 flocks and 4 harems) and 11 (4 flocks and 7 harems) game farms across England, respectively (Table 1). Potential study sites were initially identified through the Game Farmers Association. Individual sites were visited in order to explain our requirements, the only selection was to ensure geographical spread, otherwise the farms would be considered as typical of the industry. During the study, five game farms provided data on both flock and harem laying systems. Due to variations in labour and management constraints between game farms, data on some aspects of the study could not be collected on all game farms. The size of the game farms used in this study were representative of the UK industry and, therefore, varied considerably, with the total number of laying hens on each farm ranging from 200 to 15,000. Although a few game farms sourced their birds from local shooting estates, most (76%) had over-wintered their laying flocks in large outdoor pens or inside large barns. Birds were kept in laying pens for between 78 and 133 days (= 101.6, SE = ±5.1) in 2006 and for between 89 and 125 days (= 97.3, SE = ±4.5) in 2007. Flock size and stocking density in laying pens varied between sites (Table 2).

Table 1. Location and participation of game farms.

Location / Study
Spectacles / Bits
Flock / Harem
2006 / 2007 / 2006 / 2007 / 2005 / 2006 / 2007
Berkshire 1 / * / *
Berkshire 2 / * / *
Devon / *
Dorset / *
Gloucestershire 1 / *
Gloucestershire 2 / *
Hampshire 1 / * / * / *
Hertfordshire / *
Lancashire 1 / *
Lancashire 2 / *
Leicestershire / *
Middlesex / * / *
Nottinghamshire / * / *
Oxfordshire / * / *
Powys / *
Shropshire 1 / * / *
Shropshire 2 / *
Somerset / *
Staffordshire 1 / * / * / *
Staffordshire 2 / * / *
Suffolk 1 / * / *
Suffolk 2 / *
Warwickshire 1 / * / * / *
Warwickshire 2 / *
Warwickshire 3 / *
Wiltshire / *
Worcestershire / * / *
Yorkshire 1 / *
Yorkshire 2 / *

* denotes participation in study.

Table 2. Stocking details of pheasant laying pens on game farms across England, 2006 and 2007.

Laying system / Number of birds / Stocking density (birds/m2)
Hens / Cocks
n / Mean / SE / Mean / SE / Mean / SE
Flock / 15 / 92.00 / 15.30 / 12.47 / 2.18 / 0.31 / 0.03
Harem / 11 / 8.12 / 0.52 / 1.00 / 0.00 / 0.89 / 0.13

On each game farm, two identical pens located next to each other were identified and randomly assigned either spectacled or non-spectacled birds. Management of laying pens was according to normal practice and was identical for each treatment pen apart from non-routine medications or treatments. Pheasants in both treatment pens were of the same strain and from the same over-wintered flock or caught on the same shooting estate. Game farmers were required to keep detailed records of housing, feed usage, egg collections, medications and treatments, incidences of mycoplasmosis, mortality and unusual events. All sites were issued a Standard Operating Procedure at the beginning of the study (Appendix I)