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British Poultry Science Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/cbps20
Behaviour of laying hens in cages with nest sites M. C. Appleby
a
a
Edinburgh School of Agriculture , West Mains Road, Edinburgh, EH9 3JG, Scotland Published online: 08 Nov 2007.
To cite this article: M. C. Appleby (1990) Behaviour of laying hens in cages with nest sites, British Poultry Science, 31:1, 71-80, DOI: 10.1080/00071669008417232 To link to this article: http://dx.doi.org/10.1080/00071669008417232
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/ page/terms-and-conditions
British Poultry Science (1990) 31: 71-80
BEHAVIOUR OF LAYING HENS IN CAGES WITH NEST SITES M. C. APPLEBY Edinburgh School of Agriculture, West Mains Road, Edinburgh EH9 3JG, Scotland
Downloaded by [University of Montana] at 22:27 02 April 2015
Received for publication 27th April 1989
Abstract 1. Behaviour of ISA Brown hens was compared in cages with and without nest sites provided, to determine the characteristics necessary for such nest sites and whether part of the existing cage area could be modified to form an acceptable nest site. 2. There were 5 treatments: control (C); a wooden surround in one rear corner of the cage (S); a fibreglass rollaway hollow in one rear corner of the cage (H); a hollow and a surround (H/S); a nest box attached to the back of the cage, containing a hollow (N). 3. Use of rollaway hollows was limited, unless they were blocked and wood shavings were added, when 55 to 60% of eggs were laid in them. There were also problems with soiling of hollows. 4. When hollows were blocked, most hens used them in treatments H/S and N, suggesting that substrate and surroundings both contributed to acceptability of nest sites. 5. Pre-laying behaviour in sites within the cage was disturbed and sometimes abnormal. In addition, these sites were not used for other activities, thus limiting the space available. 6. For pre-laying behaviour to be expressed satisfactorily in cages, an additional nesting area, such as a nest box or boxes, is probably necessary. INTRODUCTION
When laying hens are in feral conditions, or housed in pens or semiextensive systems, their pre-laying behaviour includes nest-site selection and nesting behaviour (Wood-Gush, 1954; Duncan et al., 1978). In cages, the opportunity to perform such behaviour is restricted and the reaction of at leastsome strains of hens indicates frustration (Wood-Gush and Gilbert, 1969; Wood-Gush, 1972). Inability to perform normal pre-laying behaviour is generally assessed as one of the most important problems for the welfare of hens in cages (Farm Animal Welfare Council, 1986). One response to such problems is to develop alternative husbandry systems, but it may also be possible to modify intensive systems. Getaway cages are modified cages for 10 to 40 birds which provide nest boxes, as well as other facilities (Bareham, 1976; Elson, 1976; Wegner, 1981). However, hens do not always use the nest boxes and there are 71
Downloaded by [University of Montana] at 22:27 02 April 2015
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M. C. APPLEBY
other problems with this system (Elson, 1981). Another approach to modifying cages has been taken at Edinburgh, retaining the small colony sizes found to be successful in conventional cages. In a pilot study, most eggs were laid in nest boxes (Robertson et al., 1989). In all these studies, and in other experimental work on nesting behaviour in cages (Brantas, 1980), the usual approach has been to provide traditional wooden nest boxes containing loose nesting material. In this paper I examine in more detail the characteristics which are necessary for nest sites in cages. There are two main aspects to a nest site: the substrate and its surroundings. Given the choice, hens generally choose mouldable, manipulable substrates. However, interpretation of this is difficult, because they will lay consistently in rollaway nests if litter nests are not available. It seems likely that loose nesting material acts as a supernormal stimulus (Duncan and Kite, 1989). Furthermore, some hens, particularly from medium-weight strains, will sit and perform vacuum nest building on wire mesh (Wood-Gush, 1972). As with other vacuum activities such as dust bathing (Vestergaard, 1982), it is not clear whether this indicates high motivation or a low behavioural threshold for triggering it (Duncan, 1985). One way of examining this is to investigate whether these hens do react to the other aspect of nest sites, their surroundings. Experiments with nest boxes suggest that the most important feature of a nest site's surroundings is its degree of enclosure (Appleby et al., 1984; Appleby and McRae, 1986). In the present experiment I investigate the effects of providing rollaway hollows and enclosed areas on the pre-laying behaviour of hens in cages.
MATERIALS AND METHODS
There were 30 experimental cages, 450 mm wide, 600 mm deep and 450 mm high at the back. The back, sides and roof were 12 SWG wire (2-64 mm); the floor was of 14 SWG (2-03 mm), with mesh size 25 X 37 mm and slope 8°. These cages were in 6 blocks of 5, arranged in two rows facing each other in a controlled-environment house. There were 5 treatments, with 6 replicates of each, one in each block. Within blocks, treatments were randomised for position. The treatments are illustrated in Fig. 1 and listed below. Control (C): no nest site provided. Surround (S): a nest site 250 X 250 mm was defined in one rear corner of the cage by a wooden surround, with two complete sides against the back and side of the cage, two partial sides 30 mm wide and a roof. Hollow (H): a rollaway nest hollow was fitted in one rear corner of the cage. This was a round, fibreglass hollow, 90 mm deep, with a central hole leading to an egg collection channel. The hollow was 210 mm across, modelled on the shape that a hen makes in loose nesting material (Duncan and Kite, 1989), with a square fibreglass rim 250 X 250 mm. Hollow/Surround (H/S): a nest hollow and a wooden surround were fitted in one rear corner of the cage. Nest Box (N): a wooden nest box 250 X 250 mm and 450 mm high was
NEST SITES IN CAGES
73
Downloaded by [University of Montana] at 22:27 02 April 2015
s
FIG. 1.—The experimental cages: control cages (C) had no nest site provided; other treatments had a wooden surround (S), a rollaway hollow (H), a hollow and a surround (H/S) or a hollow in a nest box (N).
attached to the back of the cage. It contained a nest hollow with the rim flush with the floor of the cage. ISA Brown layers were purchased at 20 weeks old from a farm where they had been reared on litter, and stocked at 4 per cage. This gave a cage area of 675 cm2/bird; the nest box in treatment N gave an additional 156 cm2/bird. All birds were wing-tagged. Layers mash was provided in a food trough at the front of the cage, renewed at 08.00 h daily, and water by nipple drinkers. The photoperiod, initially from 08.00 to 16.00 h, was increased by 20 min twice per week. Eggs were collected at 13.00 h; for the three treatments with nest hollows separate records were kept for eggs laid in the hollow and those laid elsewhere in the cage. Few eggs were laid in the hollows at first, so the central holes were blocked and wood shavings were added for 4 weeks, first in half the cages (cages 1 to 15, in weeks 25 to 28) and then in the other half (cages 16 to 30, in weeks 27 to 30). These shavings were renewed daily. Observations of how birds used the cage area were made in weeks 23 and 31. Every 30 min, a scan was made of all the cages, recording the position and activity of each bird. This was done for three periods of 90 min each day so that over 6 d the period 09.00 to 18.00 h was covered three times. Nesting behaviour was observed in weeks 27 to 28. All birds under observation were palpated at lights-on to determine which had hard-shelled eggs ready to lay, and observations continued until most or all of these birds had laid, usually after 4 to 5 h. Two methods of observation were used. In the first, one or two cages were watched continuously, and the nesting behaviour of all hens in those cages was noted. Records were made of nest entries (distinct, forward movement into the nest site, usually with lowered head (Wood-Gush, 1954)), disturbances to nesting birds and ovipositions. In the second, 5 cages in a block were scanned and hens' positions were drawn on to a
74
M. C. APPLEBY
plan of the cage at 5 min intervals. Nest entries and ovipositions were also recorded. For each hen, the 12 drawings before oviposition were used to determine the proportion of the final hour which was spent in the final laying position. Non-parametric statistics (Siegel, 1956) were used to test data from different individual birds or cages, as appropriate.
RESULTS
Downloaded by [University of Montana] at 22:27 02 April 2015
Use of cage area
In all treatments, the majority of time was spent in the front half of the cage: 74% in control cages, 73% in cages with nest boxes and 76 to 79% in others. These figures were similar, but there was some indication that use of the rear half of the cage was constrained by the nest sites in treatments S, H and H/S. Certainly the nest sites themselves were rarely used: 6% of records were in the nest site in treatment S (23% of the area), 0% in the hollow in treatment H (13% of the area), 1% in the hollow in treatment H/S (13% of the area) and 0% in the hollow in treatment N (10% of the area). The 6% use of the nest site in treatment S included various activities such as preening and resting; in the other treatments those few birds which were seen in the nest site were mostly nesting or laying. In the three treatments with nest hollows, more time was spent standing or sitting on the edge of the fibreglass rim: 7, 5 and 3% in treatments H, H/S and N respectively. Casual observations also suggested that birds often roosted in this position at night. This led to problems with defaecation in the nest hollows, particularly in treatments H and H/S. This sometimes produced soiled eggs, but not always: birds nesting in the hollows often cleaned the hollow by the action of their feet before laying, and holes in the egg collection channel allowed faeces to fall through before the egg followed. Use of nest sites
In the three treatments with nest hollows, less than 20% of eggs were laid in the hollows in the first 4 weeks of lay (Fig. 2). Consequently, the rollaway holes were blocked and wood shavings were added, for 4 weeks. The proportion of eggs laid in the hollows immediately increased, and continued to increase during this period, to a maximum of 60% in cages 1 to 15 and 55% in cages 16 to 30. This proportion differed significantly between treatments: for example in cages 1 to 15 the maximum was 29% in treatment H, 72% in treatment H/S and 79% in treatment N (Kruskal-Wallis test between cages: //=5-6, P
British Poultry Science Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/cbps20
Behaviour of laying hens in cages with nest sites M. C. Appleby
a
a
Edinburgh School of Agriculture , West Mains Road, Edinburgh, EH9 3JG, Scotland Published online: 08 Nov 2007.
To cite this article: M. C. Appleby (1990) Behaviour of laying hens in cages with nest sites, British Poultry Science, 31:1, 71-80, DOI: 10.1080/00071669008417232 To link to this article: http://dx.doi.org/10.1080/00071669008417232
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/ page/terms-and-conditions
British Poultry Science (1990) 31: 71-80
BEHAVIOUR OF LAYING HENS IN CAGES WITH NEST SITES M. C. APPLEBY Edinburgh School of Agriculture, West Mains Road, Edinburgh EH9 3JG, Scotland
Downloaded by [University of Montana] at 22:27 02 April 2015
Received for publication 27th April 1989
Abstract 1. Behaviour of ISA Brown hens was compared in cages with and without nest sites provided, to determine the characteristics necessary for such nest sites and whether part of the existing cage area could be modified to form an acceptable nest site. 2. There were 5 treatments: control (C); a wooden surround in one rear corner of the cage (S); a fibreglass rollaway hollow in one rear corner of the cage (H); a hollow and a surround (H/S); a nest box attached to the back of the cage, containing a hollow (N). 3. Use of rollaway hollows was limited, unless they were blocked and wood shavings were added, when 55 to 60% of eggs were laid in them. There were also problems with soiling of hollows. 4. When hollows were blocked, most hens used them in treatments H/S and N, suggesting that substrate and surroundings both contributed to acceptability of nest sites. 5. Pre-laying behaviour in sites within the cage was disturbed and sometimes abnormal. In addition, these sites were not used for other activities, thus limiting the space available. 6. For pre-laying behaviour to be expressed satisfactorily in cages, an additional nesting area, such as a nest box or boxes, is probably necessary. INTRODUCTION
When laying hens are in feral conditions, or housed in pens or semiextensive systems, their pre-laying behaviour includes nest-site selection and nesting behaviour (Wood-Gush, 1954; Duncan et al., 1978). In cages, the opportunity to perform such behaviour is restricted and the reaction of at leastsome strains of hens indicates frustration (Wood-Gush and Gilbert, 1969; Wood-Gush, 1972). Inability to perform normal pre-laying behaviour is generally assessed as one of the most important problems for the welfare of hens in cages (Farm Animal Welfare Council, 1986). One response to such problems is to develop alternative husbandry systems, but it may also be possible to modify intensive systems. Getaway cages are modified cages for 10 to 40 birds which provide nest boxes, as well as other facilities (Bareham, 1976; Elson, 1976; Wegner, 1981). However, hens do not always use the nest boxes and there are 71
Downloaded by [University of Montana] at 22:27 02 April 2015
72
M. C. APPLEBY
other problems with this system (Elson, 1981). Another approach to modifying cages has been taken at Edinburgh, retaining the small colony sizes found to be successful in conventional cages. In a pilot study, most eggs were laid in nest boxes (Robertson et al., 1989). In all these studies, and in other experimental work on nesting behaviour in cages (Brantas, 1980), the usual approach has been to provide traditional wooden nest boxes containing loose nesting material. In this paper I examine in more detail the characteristics which are necessary for nest sites in cages. There are two main aspects to a nest site: the substrate and its surroundings. Given the choice, hens generally choose mouldable, manipulable substrates. However, interpretation of this is difficult, because they will lay consistently in rollaway nests if litter nests are not available. It seems likely that loose nesting material acts as a supernormal stimulus (Duncan and Kite, 1989). Furthermore, some hens, particularly from medium-weight strains, will sit and perform vacuum nest building on wire mesh (Wood-Gush, 1972). As with other vacuum activities such as dust bathing (Vestergaard, 1982), it is not clear whether this indicates high motivation or a low behavioural threshold for triggering it (Duncan, 1985). One way of examining this is to investigate whether these hens do react to the other aspect of nest sites, their surroundings. Experiments with nest boxes suggest that the most important feature of a nest site's surroundings is its degree of enclosure (Appleby et al., 1984; Appleby and McRae, 1986). In the present experiment I investigate the effects of providing rollaway hollows and enclosed areas on the pre-laying behaviour of hens in cages.
MATERIALS AND METHODS
There were 30 experimental cages, 450 mm wide, 600 mm deep and 450 mm high at the back. The back, sides and roof were 12 SWG wire (2-64 mm); the floor was of 14 SWG (2-03 mm), with mesh size 25 X 37 mm and slope 8°. These cages were in 6 blocks of 5, arranged in two rows facing each other in a controlled-environment house. There were 5 treatments, with 6 replicates of each, one in each block. Within blocks, treatments were randomised for position. The treatments are illustrated in Fig. 1 and listed below. Control (C): no nest site provided. Surround (S): a nest site 250 X 250 mm was defined in one rear corner of the cage by a wooden surround, with two complete sides against the back and side of the cage, two partial sides 30 mm wide and a roof. Hollow (H): a rollaway nest hollow was fitted in one rear corner of the cage. This was a round, fibreglass hollow, 90 mm deep, with a central hole leading to an egg collection channel. The hollow was 210 mm across, modelled on the shape that a hen makes in loose nesting material (Duncan and Kite, 1989), with a square fibreglass rim 250 X 250 mm. Hollow/Surround (H/S): a nest hollow and a wooden surround were fitted in one rear corner of the cage. Nest Box (N): a wooden nest box 250 X 250 mm and 450 mm high was
NEST SITES IN CAGES
73
Downloaded by [University of Montana] at 22:27 02 April 2015
s
FIG. 1.—The experimental cages: control cages (C) had no nest site provided; other treatments had a wooden surround (S), a rollaway hollow (H), a hollow and a surround (H/S) or a hollow in a nest box (N).
attached to the back of the cage. It contained a nest hollow with the rim flush with the floor of the cage. ISA Brown layers were purchased at 20 weeks old from a farm where they had been reared on litter, and stocked at 4 per cage. This gave a cage area of 675 cm2/bird; the nest box in treatment N gave an additional 156 cm2/bird. All birds were wing-tagged. Layers mash was provided in a food trough at the front of the cage, renewed at 08.00 h daily, and water by nipple drinkers. The photoperiod, initially from 08.00 to 16.00 h, was increased by 20 min twice per week. Eggs were collected at 13.00 h; for the three treatments with nest hollows separate records were kept for eggs laid in the hollow and those laid elsewhere in the cage. Few eggs were laid in the hollows at first, so the central holes were blocked and wood shavings were added for 4 weeks, first in half the cages (cages 1 to 15, in weeks 25 to 28) and then in the other half (cages 16 to 30, in weeks 27 to 30). These shavings were renewed daily. Observations of how birds used the cage area were made in weeks 23 and 31. Every 30 min, a scan was made of all the cages, recording the position and activity of each bird. This was done for three periods of 90 min each day so that over 6 d the period 09.00 to 18.00 h was covered three times. Nesting behaviour was observed in weeks 27 to 28. All birds under observation were palpated at lights-on to determine which had hard-shelled eggs ready to lay, and observations continued until most or all of these birds had laid, usually after 4 to 5 h. Two methods of observation were used. In the first, one or two cages were watched continuously, and the nesting behaviour of all hens in those cages was noted. Records were made of nest entries (distinct, forward movement into the nest site, usually with lowered head (Wood-Gush, 1954)), disturbances to nesting birds and ovipositions. In the second, 5 cages in a block were scanned and hens' positions were drawn on to a
74
M. C. APPLEBY
plan of the cage at 5 min intervals. Nest entries and ovipositions were also recorded. For each hen, the 12 drawings before oviposition were used to determine the proportion of the final hour which was spent in the final laying position. Non-parametric statistics (Siegel, 1956) were used to test data from different individual birds or cages, as appropriate.
RESULTS
Downloaded by [University of Montana] at 22:27 02 April 2015
Use of cage area
In all treatments, the majority of time was spent in the front half of the cage: 74% in control cages, 73% in cages with nest boxes and 76 to 79% in others. These figures were similar, but there was some indication that use of the rear half of the cage was constrained by the nest sites in treatments S, H and H/S. Certainly the nest sites themselves were rarely used: 6% of records were in the nest site in treatment S (23% of the area), 0% in the hollow in treatment H (13% of the area), 1% in the hollow in treatment H/S (13% of the area) and 0% in the hollow in treatment N (10% of the area). The 6% use of the nest site in treatment S included various activities such as preening and resting; in the other treatments those few birds which were seen in the nest site were mostly nesting or laying. In the three treatments with nest hollows, more time was spent standing or sitting on the edge of the fibreglass rim: 7, 5 and 3% in treatments H, H/S and N respectively. Casual observations also suggested that birds often roosted in this position at night. This led to problems with defaecation in the nest hollows, particularly in treatments H and H/S. This sometimes produced soiled eggs, but not always: birds nesting in the hollows often cleaned the hollow by the action of their feet before laying, and holes in the egg collection channel allowed faeces to fall through before the egg followed. Use of nest sites
In the three treatments with nest hollows, less than 20% of eggs were laid in the hollows in the first 4 weeks of lay (Fig. 2). Consequently, the rollaway holes were blocked and wood shavings were added, for 4 weeks. The proportion of eggs laid in the hollows immediately increased, and continued to increase during this period, to a maximum of 60% in cages 1 to 15 and 55% in cages 16 to 30. This proportion differed significantly between treatments: for example in cages 1 to 15 the maximum was 29% in treatment H, 72% in treatment H/S and 79% in treatment N (Kruskal-Wallis test between cages: //=5-6, P
