Dustbathing Research Articles

Floor versus cage rearing: effects on production, egg quality and physical condition of laying hens housed in furnished cages

The influences of floor- and cage-rearing on egg production, egg quality and physical condition were investigated in laying hens housed in furnished cages. Two groups of 180 Isa Brown commercial layer pullets were reared in cages (CR) or floor pens (FR) and transferred to furnished cages, where their production, egg quality and physical condition was observed throughout the laying period (18-78wks of age). At 17 weeks of age, hens were placed in one of 36 furnished cages with 10 birds in each cage, each containing a nest box, perches, a dust bath, and abrasive strips. From 19 to 78 weeks of age, egg production data were collected daily. Commercial egg quality was assessed monthly. At, 19 and 78 weeks of age, claw length and feather cover were visually assessed using a four-point scale in a sample (10%) of hens. Production variables were above breeders’ standards and not significantly affected by rearing system. Dirty eggs and cracked eggs were more frequent in FR birds. Meat spots were significantly more frequent in FR hens at middle lay, but less frequently at the end of the laying period. Rearing system did not influence egg and yolk weight or unit Haugh and shell colour. Among FR hens, eggshell density, thickness and mass were significantly lower at the end of the laying period. Rearing system did not affect claw length, but the plumage of FR hens was negatively affected at the end of production cycle.

The effects of a perch, dust bath, and nest box, either alone or in combination as used in furnished cages, on the welfare of laying hens

This experiment examined the welfare-related effects of individual furniture items alone or in combination in a factorial experiment using Hy-Line Brown hens housed in 8-bird furnished cages. Welfare was assessed during two 8-wk sampling periods commencing at 29 and 59 wk of age. Measurement of stress, immunology, feather, foot and claw condition, and behavior were taken, and bone strength was measured at the end of the experiment. With the exception of the positive effects of a perch on bone strength, any effects of furniture items were relatively small, even though the furniture was extensively used. Although there were changes in behavior and small changes in feather, foot, and claw condition, it is unclear whether these changes have any meaningful implications for welfare. In this experiment there were 2 additional external control treatments for a small study that examined the effects of increasing space per bird (8 birds in single- and double-width cages) and the effects of group size (8 and 16 birds in double-width cages); using similar methodologies, these treatments showed differences in egg corticosterone concentrations and evidence of immunosuppression. Together, these data suggest that although furniture when present was well-used, any effects of furniture on hen welfare measured by physical and physiological traits, other than the benefit of a perch on bone strength, were smaller than effects of group size and space allowance.

Effects of separation of resources on behaviour, physical condition and production of laying hens in furnished cages

1. Based on our previous studies, we designed a medium-sized furnished cage with a dust bath and nest box on both sides of the cage (MFS) and evaluated its usefulness. 2. We used 180 White Leghorn layers. At the age of 17 weeks, the birds were distributed at random into one of the 4 cage designs: conventional cages (CC; 6 cages and 5 hens per cage), small (SF; 6 cages and 5 hens per cage) and medium furnished cages (MFL; 6 cages and 10 hens per cage) with a ‘localised’ dust bath and nest box on one side of the cage, and MFS (6 cages and 10 hens per cage). The total allocation of resources per bird was similar for all furnished cage designs. Behaviour, physical condition and production were measured in each cage. 3. Moving was more frequent in MFS and MFL than in CC and SF. The proportion of hens performing aggressive pecking and severe feather pecking was higher in MFL than CC and SF. These aggressive interactions occurred frequently in the dust bath area in MFL; however, these tendencies were not found in MFS. Egg production and egg mass were lower in MFL than in SF, while the production in MFS was similar to those in CC and SF. MFS hens laid eggs on the cage floor more often than in MFL. 4. In conclusion, these results demonstrate the possible usefulness of MFS. However, some inconsistent results and ways of improving MFS design were also identified.

Rearing system and behavioural adaptation of laying hens to furnished cages

The influences of floor and cage-rearing on behavioural adaptation to furnished cages were investigated in laying hens. Two groups of 180 Isa Brown commercial layer pullets were reared in cages (CR) or floor pens (FR) and transferred to furnished cages, where their behavioural adaptation was observed throughout the laying period (18-78 wks of age). At 17 weeks of age, hens were placed in one of the 36 furnished cages with 10 birds in each cage, each containing a nest box, perches, a dust bath, and abrasive strips. At 50 and 54 weeks of age, direct visual observation and video recording were used to assess hen’s behaviour. From 21 weeks of age, the dust-bath activities of leg-banded hens in eight cages per treatment were recorded. The amount of time spent walking was higher (3.5% vs. 1.8%) and perching was lower (7.5% vs. 13.4%) in CR hens than in FR hens (P<0.05). The use of dust baths and dust bathing behaviour increased throughout the laying period. The proportion of hens present at the sand bath area increased from 9.2% at 21 weeks to 21.4% at 72 weeks and the proportion of hens dust bathing increased from 4.7% to 21.0% (P<0.05). At 72 weeks of age, all dust-bath parameters were higher (P<0.05) in FR hens than in CR hens.

Relation between social order and use of resources in small and large furnished cages for laying hens

1. The objective was to determine the relation between social rank and use of resources in a small furnished cage with sufficient resources per hen (SF) and a commercial large one with less adequate allowance of facilities per hen (LF). 2. Ninety-two cross layers were used. At the age of 16 weeks, the hens were divided at random into two groups. There were 4 furnished cages with 5 birds per cage and 4 large furnished cages with 18 birds per cage. The dominance hierarchy was determined, in which highest, medium and lowest ranking hens in each cage were identified. Behaviour, use of facilities and physical conditions of these hens were measured (one in each rank category in SF, two in each in LF). 3. Dustbathing and litter scratching were more frequent in the high ranking hens than the medium and low ranked hens in LF, while no significant difference was found between them in SF. 4. No significant difference between SF and LF was found in use of nest boxes. However, pre-laying sitting tended to be less frequent in low ranking than medium and high ranking hens in LF (Social order × Cage design). In the nest box most of time was spent in pre-laying sitting by SF hens, LF high and medium ranked hens (average 94·9%). However, LF low ranking hens spent their time escaping (33·1%), pre-laying sitting (27·7%) standing (25·7%) and moving (13·5%) in the nest. 5. In the large furnished cages with less facilities per hen, high ranking hens may be expected to have priority using the dust bath. In contrast, low ranking hens rarely performed nesting behaviour fully, and spend more time using the nest box as a refuge than for laying.

The role of the veterinarian in animal welfare

For many veterinarians, animal welfare is a matter of animal health: As long as an animal is healthy, it is also happy. For the past forty years, however, behaviour biologists have shown repeatedly that, whereas poor health contributes to poor welfare, the opposite is not necessarily the case. There is more to good welfare than good health. Numerous studies have shown that, despite many generations of selection for various traits, the behavioural repertoire of domestic animals is almost identical to that of their wild ancestors. A broiler chicken has a similar demand for dust bathing as a jungle fowl. A thoroughbred racehorse has the same demand for social contact as the Przwalski horse. These are just two of many other examples. Consequently, to ensure a certain level of welfare in our domestic animals, it is important that they are able to perform their species-specific behaviour beyond eating behaviour, drinking behaviour, eliminative behaviour and resting behaviour. And that's where the controversy begins! Which elements of the animal's ethogram are essential and which ones are not? Must a prey animal show flight behaviour regularly to be happy? Must a well-fed animal show foraging behaviour to be content? Is social contact through bars enough contact? The controversy consists of, on the one side, practitioners or producers that need to house and manage animals in such a way that their production is productive and, on the other side, animal protection people or animal rights people who are against any exploitation of the domestic animals. As with most issues, obviously the optimum lies somewhere in between these two extremes. We all have to compromise and so must our domestic animals. In return for regular food, water, shelter and medical care, the animals must give up some of their freedom. But how much they must give up, how restrictively we can keep them with good conscience, is a matter of dispute. The veterinary profession plays a key role in the controversy in that it possesses a detailed knowledge of both camps. Practicing veterinarians and veterinary inspectors are in regular contact with the animals, either in the clinic or during visits to the farms, either to treat sick animals, to institute preventive measures, or to control that legislation is being followed. At the same time veterinarians possess (or should possess) the scientific background that enable them to judge the welfare of their patients and clients. Public concern for the welfare of domestic animals is likely to increase in the future. At the present time behaviour biologists still struggle with the difficult task of measuring happiness in the animals. Similarly, programs for monitoring welfare in praxis are being developed in many countries. An important question in these developments is how the veterinary profession can best prepare itself for future challenges, both in the veterinary curriculum and in terms of continued education.

Role of loose feathers on the development of feather pecking in laying hens

1. The effect of the presence of loose feathers (on the floor) on the behaviour and plumage condition of laying hens (Lohmann Silver, LS) was studied during the rearing and laying periods. 2. From one day old, 60 birds in each of 4 straw-bedded pens (n = 240 in total) with 6·5 birds/m2 were either kept under conventional rearing and management conditions (CT: control group with feathers on the floor; n = 120) or in pens from which the feathers were collected from the floor 4 times/week (FR: feathers removed; n = 120). Fifty birds from each of these 4 groups (n = 200 in total) were randomly selected at the age of 16 weeks and allocated to 4 identical pens in a poultry layer house (PH; with perches and 1/3 slatted floor) with access to an outside area (winter garden, WG) at a stocking density of 6 birds/m2 in both PH and WG. 3. Observations on feather pecking and other behaviours (feeding, drinking, preening, standing, sitting, foraging, moving and dust bathing) were carried out at 8 ages: 6, 10, 15 (rearing period), 20, 25, 30, 35 and 40 weeks (laying period). Feather scoring was carried out at 15, 32 and 39 weeks of age. 4. There were no differences in feather pecking rates, forms (gentle, severe and aggressive pecks) as well as in the plumage condition between groups at the end of the rearing period. 5. Birds in the FR group exhibited lower rates and less severe feather pecking during the laying period. Accordingly, birds in the control group had worse feather condition at 32 and 39 weeks of age. Feather pecking rates within groups were, in general, greater in the afternoon compared to the morning periods. Birds in the control group were more active in walking. 6. Wings, rump, tail and back were the main targets for feather pecking. The majority of feather pecking occurred on the floor (66%) followed by feeding area (26%), perches (4%) and slats (4%). 7. Our results suggest that loose feathers on the floor may play an important role in the development and severity of feather pecking behaviour in laying hens and support the hypothesis (McKeegan and Savory, 1999) that feather pecking can be viewed as redirected foraging behaviour.

Bone Mineral Density and Breaking Strength of White Leghorns Housed in Conventional, Modified, and Commercially Available Colony Battery Cages

Limited opportunity for movement and load-bearing exercise for conventionally caged laying hens leads to bone loss and increased susceptibility to osteoporosis, bone fractures, and cage layer fatigue, all of which compromise hen welfare and have negative consequences for production. The objective of this study was to compare bone mineral density (BMD) and strength measures of White Leghorns housed in conventional battery cages (CONV), cages modified to incorporate a nest box and perch (MOD), and commercially available, furnished colony cages with (CWDB) or without (CWODB) a raised dust bath. Hens reared on floor litter were randomly allocated to 1 of 4 cage systems at 19 wk of age. Hen-day production and egg quality were measured between 20 and 64 wk. At 65 wk, hens were killed, and right femur, tibia, and humerus were excised. Bone mineral density was assessed using quantitative computed tomography, and breaking strength was measured with an Instron Materials Tester. In the femur and tibia, CONV hens exhibited lower total BMD, bone mass, cortical bone area, cortical bone mass, and bone-breaking strength than CWDB, CWODB, and MOD hens. Density and cross-sectional area of bone in the trabecular space was highest in CONV. In the humerus, total and cortical BMD and mass and breaking strength values were higher for colony-housed birds than hens in CONV and MOD. The MOD birds did not exhibit increased humeral BMD or strength measures over CONV hens. These findings provide evidence that hens housed in modified and colony cages, furnished systems that promote load-bearing movement, are better able to preserve cortical structural bone than conventionally caged hens and simultaneously have stronger bones. Furthermore, inclusion of raised amenities that encourage wing loading is necessary to reduce humeral cortical bone loss. The overall absence of correlation between egg production or quality and bone quality measures also suggests that improved bone quality in CWDB, CWODB, and MOD furnished cages is not the result of lowered egg production or quality.

Effects of separation of resources on behaviour of high-, medium- and low-ranked hens in furnished cages

In our previous studies, we demonstrated that dominant hens had priority in using the dust bath, resulted in increased competition for the resource. It seemed that the problem was that the resource was placed on one side of the cage (‘localised’). Therefore, we designed a medium-sized furnished cage with a dust bath and nest box on both sides of the cage (‘separated’, MFS). To evaluate the effects of separation of these resources, we compared the behaviour of high-, medium- and low-ranked hens in MFS cage with that in small (SF) and medium furnished (MFL) cages with a localised resource. In total, 150 White Leghorn layers were used. At the age of 17 weeks, the hens were randomly divided into three groups and moved to small furnished cages (SF, 90 cm wide; five birds per cage) and two types of medium furnished cages (180 cm wide; 10 birds per cage) with a nest box and dust bath on both sides (MFS) and a nest box and dust bath on one side of the cage (MFL). The total dust bath and nest box areas per hen were same for the three cages. The dominance hierarchy was determined by observing the aggressive interactions and by this high-, medium- and low-ranked hens in each cage were identified. The behaviour, use of facilities and physical condition of these hens were measured. Data were analysed by using repeated measure ANOVA. A significant interaction between social order and cage design was found in the proportions of time spent in the dust bath and on performing dust-bathing (both P < 0.001), and these proportions tended to be higher in higher-ranked hens in SF and MFL. Conversely, the MFS low-ranked hens tended to use the dust bath more than the SF and MFL low-ranked hens. Thus, hens from each rank used the dust bath equally in MFS, though the MFS high-ranked hens tended to use the resource less than the SF and MFL high-ranked hens. While the frequency of pre-laying sitting was lower among low-ranked hens ( P < 0.05), the proportion of time in the nest box was higher among low- than high-ranked hens ( P < 0.01). The low-ranked hens spent more time performing escaping, moving and standing in the nest box. In conclusion, it is suggested that separation of the dust bath to two locations would be an effective arrangement to promote more equal usage of the dust bath by hens from each rank in the furnished cages. It was also confirmed in the present study that nest boxes were not only used for laying eggs but also as a refuge by lower ranked hens.

ROADSIDE FORAGING BY KANGAROO RATS IN A GRAZED SHORT-GRASS PRAIRIE LANDSCAPE

We used live-trapping and foraging experiments to describe use of roadside vegetation by kangaroo rats (Dipodomys ordii) in short-grass prairie in Colorado, and to determine whether this species' perception of predation risk differed between roadside habitats, where predators were expected to be most active, and locations 120 m into adjacent grazed pastures. Giving-up densities (GUDs) were measured in paired seed trays placed beneath saltbush (Atriplex canescens) shrubs and in the open, 3 m from shrubs along transects in roadside and pasture locations. Trials were conducted on nights with a partial (1st-quarter), full, and new moon to assess how intensity of risk affected microhabitat use. Kangaroo rats were much more abundant in areas with saltbush cover than in grazed prairie, and were 4–6 times more numerous along roadsides in saltbush areas than in other locations. On dark nights and in pasture locations, foraging rates of kangaroo rats were similar in shrub trays and open trays. The fewest seeds were removed (i.e., GUDs were highest), however, in open trays along roads on moonlit nights, suggesting that kangaroo rats recognized potential risks associated with roadsides on bright nights. The high numbers of kangaroo rats along roads suggest that benefits associated with these habitats (ease of digging, dust bathing, higher soil seed banks) exceed the costs associated with higher risk of mortality from predators and vehicles. Our results demonstrate how foraging decisions differ depending on the spatial and temporal contexts in which behaviors are measured, and underscore the potential value of less common habitats such as road margins for increasing landscape-scale diversity and wildlife habitat in grazed grasslands.

A 33-year Study of Hazel Grouse Bonasa bonasia in the Bohemian Forest, Šumava, Czech Republic: Effects of Weather on Density in Autumn

Abstract The only long-term census of hazel grouse Bonasa bonasia in Central Europe was conducted during 1972-2004 on a 100-km2 area of the Bohemian Forest, Sumava, Czech Republic. To obtain a density index in October, I recorded indirect signs of hazel grouse, such as dust bathing sites, feathers, droppings or tracks, and reactions to a whistle that imitates the male territorial song along fixed routes covering 80 km in total. During the 33 years of counting, I found no statistically significant trend in the fluctuating numbers. I also looked for the influence of weather on hazel grouse abundance. Analysis by stepwise multiple regression suggested that six weather variables were correlated with the annual rate of change of hazel grouse density in autumn, explaining 44% of the variation in density: mean temperature and total precipitation in April (highly significant positive correlations) and mean temperature and total precipitation in May and September (significant negative correlations). The results fo...

Differences of behavior, use of resources and physical conditions between dominant and subordinate hens in furnished cages

ABSTRACTThe objective of the present study was to search for differences in the behavior, use of resources and the physical condition between dominant and subordinate birds in furnished cages. In total, 60 commercial White Leghorn layers were used. At the age of 54 weeks, these birds were divided into two groups. Each group consisted of six cages with four birds per cage and six cages with six birds per cage. The dominance hierarchy was measured, to identify the highest dominant bird and the lowest subordinate bird in the hierarchy of each furnished cage. Behavioral observations using scanning techniques at 10 min intervals were conducted on the birds at 57 and 67 weeks of age for 3 days, respectively. Their physical condition (bodyweight and claw length) was also measured. Dominant birds used the dust bath more (P &lt; 0.1) and nest box less (P &lt; 0.01) than subordinate birds did. The use of the nest box decreased for subordinate birds from 57 to 67 weeks of age (P &lt; 0.05). The dominant birds performed aggression and exploring more frequently than the subordinate birds (P &lt; 0.001 and P &lt; 0.05, respectively). In the comfort behaviors, the dominant birds performed dust‐bathing, as well as the using the dust bath, more than subordinate birds did (P &lt; 0.1). In their exploring behavior, including scratching and litter pecking, dominant birds performed both behaviors more frequently, as well as using the dust bath and dust‐bathing in it, than subordinate birds did (P &lt; 0.1 and P &lt; 0.05, respectively). Aggression decreased for dominant birds from 57 to 67 weeks of age. In contrast, eating (P &lt; 0.1) as well as drinking (P &lt; 0.1) and other comfort behaviors (P &lt; 0.1) increased for subordinate birds from 57 to 67 weeks of age. There was no significant difference between dominant and subordinate birds in their physical conditions. In conclusion, dominant birds had priority to use the dust box compared with the subordinate birds in the furnished cages. Conversely, the subordinate birds stayed in the nest box more than the dominant birds did. In the furnished cages, equipping the nest box was important not only for the birds to perform nesting behavior, but also for the subordinate birds to use the facility as a refuge especially just after introduction to the cage.

Inclusion of Dust Bathing Materials Affects Nutrient Digestion and Gut Physiology of Layers

Effect of access to wood shavings and processed paper in the litter bath of modified cages on performance, gizzard activity, plumage condition, and peck damages was studied for layers fed a wheat-based diet. Egg production was similar for all treatments, but birds with access to paper showed higher feed consumption than the control birds and birds with access to wood shavings. This resulted in a corresponding difference (P < 0.05) in feed utilization. A significantly higher AMEn was observed for birds with access to wood shavings than in the control. Consumption of wood shavings and paper from the litter bath was 4 and 11 g/hen per day, respectively. Weights of empty gizzard and gizzard contents were considerably higher for birds with access to wood shavings. The median particle size in the duodenum decreased with access to wood shavings. In contrast, birds with access to paper showed a higher mean particle size in the duodenum.

Motivation to dust-bathe of laying hens housed in cages and in aviaries

New housing systems for commercial egg production, furnished cages and non-cage systems, should improve the welfare of laying hens. In particular, thanks to the presence of a litter area, these new housing systems are thought to satisfy the dust-bathing motivation of hens more than in conventional cages, in which no litter area is present. However, although apparently obvious, there is no concrete evidence that non-cage systems, particularly aviaries, satisfy hens' motivation to dust-bathe and thus improve hens' welfare in terms of dust-bathing behaviour. The aim of this study was to compare hens' dust-bathing motivation when housed for a long time under similar conditions to commercial conditions in laying aviaries (with litter) and in conventional cages (without litter). Three treatments were compared: hens reared in floor pens then housed in conventional cages, hens reared in furnished floor pens then housed in a laying aviary, and hens reared in rearing aviaries then housed in a laying aviary. All three treatments provided access to litter during the rearing period. After transfer to the laying systems, access to litter was maintained for the aviary hens but stopped for the cage hens. Twelve groups of four hens per treatment were tested 36 to 43 weeks after transfer. The hens were placed in sawdust-filled testing arenas, and latency to dust-bathe, duration and number of dust baths, and number of hens dust-bathing were recorded. Latency to dust-bathe was shorter, dust baths were longer and more numerous and more hens dust-bathed among cage hens than among aviary hens. Our results indicate that hens' motivation to dust-bathe was more satisfied in laying aviaries than in conventional cages. Thus, laying aviaries improve hens' welfare in term of dust-bathing behaviour compared with conventional cages.

Rearing factors that influence the propensity for injurious feather pecking in laying hens

Feather pecking during rearing is difficult to identify and therefore often underestimated. However, as rearing conditions will affect the behaviour of adult hens, it is important or prevent feather pecking during rearing. This paper reviews the knowledge in the scientific literature on the effect of rearing conditions on injurious pecking. Factors such as stocking density and feeding strategies during rearing are known to influence feather pecking. Minimising the differences between the rearing and laying environment via a seamless transition is likely to make a flock less prone to injurious feather pecking. This can be achieved by providing perches and substrate for foraging and dust bathing during rearing, by providing facilities (e.g. litter trays) on perforated platforms during early lay and by focussing on early access to the range.

Rearing factors that influence the propensity for injurious feather pecking in laying hens

Feather pecking during rearing is difficult to identify and therefore often underestimated. However, as rearing conditions will affect the behaviour of adult hens, it is important or prevent feather pecking during rearing. This paper reviews the knowledge in the scientific literature on the effect of rearing conditions on injurious pecking. Factors such as stocking density and feeding strategies during rearing are known to influence feather pecking. Minimising the differences between the rearing and laying environment via a seamless transition is likely to make a flock less prone to injurious feather pecking. This can be achieved by providing perches and substrate for foraging and dust bathing during rearing, by providing facilities (e.g. litter trays) on perforated platforms during early lay and by focussing on early access to the range.

Behaviour when young as a predictor of severe feather pecking in adult laying hens: The redirected foraging hypothesis revisited

It has been suggested that feather pecking in poultry results when foraging behaviour is redirected to feathers in the absence of adequate foraging incentives and that gentle feather pecking is a precursor of severe feather pecking. Associations have also been proposed between feather pecking and other behaviours including dust bathing and preening. Here, we present the results of a longitudinal study on the development of severe feather pecking in individual domestic fowl. We hypothesised that behaviour, and especially foraging and gentle feather pecking behaviour, of individual birds when young predicts severe feather pecking behaviour by the same birds when adult. To test this hypothesis, we used behavioural data collected from 192 individual White Leghorn hens (12 focal birds/group) housed continuously from hatch in 16 floor pens. Data on 34 behaviour variables recorded when the birds were young (3–15 weeks of age) were subjected to factor analysis. The resulting factors were entered as independent variables in a generalised linear model to determine their relationship with severe feather pecking by the same birds as adults (17–37 weeks of age). We found a positive association between a factor describing foraging when young and severe feather pecking when adult, and a negative association between a factor describing dust bathing when young and severe feather pecking when adult ( P < 0.05). Levels of severe feather pecking increased following the onset of lay and we found no significant association between factors describing feather pecking when young and severe feather pecking by the same individuals when adult. Most of the birds were observed to perform exploratory gentle feather pecks when young. No evidence was found that exploratory or stereotyped gentle feather pecks consistently became more severe over time but factor analysis indicated that severe feather pecking by young birds was more closely correlated with exploratory, than stereotyped, gentle feather pecking, signalling utility in distinguishing between exploratory and stereotyped gentle feather pecking in future studies. We conclude that severe feather pecking did not substitute for foraging behaviour but, rather, was more likely to emerge in adult hens that had performed relatively more foraging, and less resting and dust bathing, when young. However, none of the individual behaviour variables recorded when young could be used to identify precisely which individuals would exhibit severe feather pecking when adult.

Effects of light intensity and beak trimming on preventing aggression in laying hens

ABSTRACTThis study aimed to investigate the effects of decreased light intensity and beak trimming on aggression prevention in laying hens. In total, 181 White Leghorns were used. At 17 weeks of age, 36 birds were allocated to battery cages (three birds/cage), 36 birds to furnished cages (four birds/cage), and 109 birds were transferred to an aviary. Since aggression increased in the birds from 23 weeks of age (from 0.3% to 6.0%) especially in the furnished cages, , the light intensity during the daytime was decreased to about one‐tenth (from 680 lux to 70 lux) at 28 weeks of age. The birds in the furnished cages then had their beaks re‐trimmed lightly by using a debeaker at 29 weeks of age. Behavioral observations using scanning techniques at 10 min intervals were conducted. Feed intake, bodyweight and feather score were also measured. There was no significant difference in aggression before and after decreasing the light in all three housing systems. On the other hand, the proportion of birds showing aggression decreased significantly just after trimming and four weeks after beak trimming in the furnished cages (P &lt; 0.05 and P &lt; 0.01, respectively). The aggression also became similar to the proportions observed in the battery cages and in the aviary. In proportion to the decreased aggression, the proportion of birds eating significantly decreased (P &lt; 0.05). However, their feed intake and bodyweight did not decrease significantly. Against this decreased aggression, the proportion of birds preening significantly increased (P &lt; 0.05). Aggression was observed more frequently at the dust bath in the furnished cages and at the litter floor in the aviary (both P &lt; 0.001). The total feather score for all body parts in the birds in furnished cages increased significantly (P &lt; 0.01) from 25 to 29 weeks of age (at beak trimming), but did not increase significantly from 29 to 33 weeks of age. The increments of neck, breast and tail feather scores in the furnished cages were smaller. In conclusion, there was no significant difference in aggression between just before and after decreasing the light in any housing system. However, aggression in the furnished cages was reduced not only by decreasing the light intensity, but by additional beak trimming. Aggravation of feather conditions – especially at the neck, breast and back – was prevented by the treatment.

Behavioral changes in laying hens after introduction to battery cages, furnished cages and an aviary

ABSTRACTA variety of investigations into alternative systems and furnished cages for laying hens have been conducted, mainly in the European Union. However, comparative studies about the behavior of laying hens just after introduction to these housing systems are few. Therefore, this study aimed to investigate the changes of location and behavior of laying hens just after introduction to three housing systems. In total, 181 White Leghorns were used. Thirty‐six birds were allocated to 12 battery cages with three birds per cage (613 cm2/bird); 36 birds were allocated to nine furnished cages with four birds per cage (1170 cm2/bird); and 109 birds were allocated to an aviary (1130 cm2/bird). Direct observations using scanning techniques were conducted over 2 weeks for 4 h/day from the day following the introduction. Scan samples of location and behavior were taken at 10 min intervals. The proportion of birds that stayed at each location in the furnished cages was stable during the observation period. In the aviary, 78% of birds were observed on the floor on the first day, and thereafter the proportion linearly decreased (P &lt; 0.01). The proportions of birds eating in both the battery and furnished cages were stable, indicating that the caged birds would adjust to these environments within a short period. Display of aggression was lower in both the cages (both 0.3 ± 0.1%) than in the aviary (3.5 ± 1.0%, P &lt; 0.001), which indicates the early establishment of social order in both cage systems. In the aviary, the birds were observed eating less frequently than in both the cages on the first day, and the proportion thereafter linearly increased (P &lt; 0.01), and the use of tiered wire floors with feeders accompanied this (P &lt; 0.01). Comfort behaviors, including dust bathing, were noted less in the aviary than in the furnished cages throughout the observation period (both P &lt; 0.05). These results suggest that adjustment of aviary birds to their new environment had been delayed compared with caged birds because of the prerearing conditions and the environmental complexity of the aviary.

Effects of beak trimming and cage design on laying hen performance and egg quality

1. Conventional cages are to be replaced by furnished cages or aviary systems to improve the welfare of hens. We compared the performance and egg quality of hens reared in two designs of furnished cages and of two standard cages. We also explored the consequences of the absence of beak trimming when using these designs. 2. Hens (2028) were housed from 18 to 70 weeks of age in 108 standard cages at 6 per cage (60 cm × 63·5 cm), in 96 cages at 5 per cage (59·5 cm × 55·5 cm) or in two designs of furnished cage at 15 per cage (24 F15M cages and 36 F15P cages made by two manufacturers) which contained equipment varying in size and location (nests, dust baths and perches). Half of the hens were beak-trimmed in each design. 3. Mortality was low in beak-trimmed hens (<5%) but was unacceptably high in non-beak-trimmed hens due to cannibalism (>40%, 516 hens). Mortality was worse in standard cages than in furnished cages. Consequently, hen-housed egg production was significantly lowered in non-beak-trimmed hens. 4. Egg laying in beak-trimmed hens reared in furnished cages occurred mainly in the nest (80 and 84·8% in F15M and F15P) but also in the dust bath (13·3 and 9·4% in F15M and F15P) and in other parts of the cage (6·7 and 5·8% in F15M and F15P). 5. The total percentage of broken (visual observation) and hair-cracked eggs (candling) was high in the furnished cage designs (15·4 and 19·6% in F15M and F15P, respectively) compared with standard cage designs (8·1 and 12·2% in S6 and S5). This was mainly due to hair-cracked eggs, the highest percentages occurring in the nests, especially in the design with a narrow nest and no egg saver (11·1% in F15M compared to 17·6% in F15P) as a consequence of egg accumulation in the cradle and relatively low frequency of manual egg collection. 6. Eggshell quality (index and breaking strength) was only slightly influenced by cage effects so differences in egg breakage were attributable to impacts related to cage design. 7. It is concluded that beak trimming remains the most effective way to prevent cannibalism, although furnished cages with a large group of hens slightly reduced the incidence, and that further development and optimisation of furnished cages is needed to reach egg quality similar to standard cages.