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 cmx63.5 cm), in 96 cages at 5 per cage (59.5 cmx55.5 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.     

Development of furnished cages for laying hens

1. A 3-year trial was carried out of cages for laying hens, occupying a full laying house. The main cage designs used were 5000 cm2 in area, 50 cm high at the rear and furnished with nests and perches. F cages had a front rollaway nest at the side, lined with artificial turf. FD cages also had a dust bath containing sand over the nest. H cages had two nest hollows at the side, one in front of the other. They were compared with conventional cages 2500 cm2 in area and 38 cm high at the rear. 2. Cages were stocked with from 4 to 8 ISA Brown hens per cage, resulting in varied allowances of area, feeder and perch per bird. No birds were beak trimmed. In F and FD cages two further treatments were applied: nests and dust baths were sometimes fitted with gates to exclude birds from dust baths in the morning and from both at night; elevated food troughs, with a lip 33 cm above the cage floor, were compared with standard troughs. 3. Management of the house was generally highly successful, with temperature control achieved by ventilation. Egg production was above breeders' standards and not significantly affected by cage design. More eggs per bird were collected when there were fewer birds per cage but food consumption also then tended to be higher. 4. The number of downgraded eggs was variable, with some tendency for more in furnished cages. Eggs laid in dust baths were often downgraded. Those laid at the back of the cage were frequently dirty because of accumulation of droppings. H nests were unsuccessful, with less than 50% of eggs laid in the nest hollows. However, up to 93% of eggs were laid in front rollaways, and few of these were downgraded. 5. Feather and foot damage were generally less in furnished than in conventional cages, greater where there were more birds per cage. With an elevated food trough there was less feather damage but more overgrowth of claws. In year 2, mortality was greater in cages with more birds. 6. Pre-laying behaviour was mostly settled in front rollaway nests. Dust baths were used more for pecking and scratching than for dust bathing. Comfort behaviour was more frequent in furnished cages than conventional, although still not frequent. Locomotion was strongly affected by number of birds per cage or by space per bird, being reduced by crowding. Most birds perched at night except in one treatment providing only 10.7 cm perch per bird. 7. Behaviour was more unrestricted and varied, and physical condition was better, in furnished than in conventional cages. However, egg production will cost more in furnished cages, partly because more eggs are downgraded. Dust baths must be fitted with gates that the birds cannot open from outside, but gates for nest boxes were found unnecessary. If a low perch is fitted it must be far enough from the back of the cage for birds to walk there. 8. Where there was less space per bird (more birds per cage) than the requirements in the 1999 European Commission Directive on laying hens, there were: fewer eggs per hen, but still above the breeders' target; lower food consumption; more feather and foot damage, but less than in conventional cages; higher mortality in one trial out of three; less freedom of movement. However, the results were still very good even with 8 birds per cage, and support the principle that furnished cages provide an acceptable way of protecting the welfare of laying hens.     

Perch Arrangements in Small-Group Furnished Cages for Laying Hens

In 2 trials, including 2,768 birds in total, 3 different perch arrangements were evaluated in furnished 8-hen cages for laying hens. The hybrids used were Lohmann Selected Leghorn and Lohmann Brown in trial 1 and Hy-Line White and Hy-Line Brown in trial 2. The furnished cages were identical in all other respects than the arrangement of perches. A perch was either fitted across the cage, providing 12 cm of perch per hen, or 2 perches were installed in a cross, implying 15 cm per hen. Although the perches arranged in a cross provided more perch per hen than the single perch fitted across the cage, perch use at night by the birds was similar or lower as compared with the single perch. Hence, the way perches are arranged in the cage may be as important as perch length itself to achieve a high use at night. Perch arrangement did not affect production, mortality, or egg quality. Compared with a conventional battery cage, also included in the trials, hygiene was inferior in the furnished cages, but there was no difference in proportions of dirty eggs. Differences in proportions of cracked eggs were found between furnished and conventional cages in 1 of the trials. However, on the whole, production, mortality, and egg quality were at similar levels in all cage models. Genotype differences were found in production traits, egg quality, hygiene, and in the use of perches and nests.     

Effects of group size on performance,health and birds’ use of facilities in furnished cages for laying hens

A total of 1584 Lohmann Selected Leghorn hens were kept in 144 modified cages furnished with—perch, nest and sandbath for 5, 6, 7 or 8 hens per cage or in 162 conventional cages for 4 hens. Cage floor area was 600 cm² per hen excluding nest and sandbath. Doors to nests and sandbaths were time monitored. Production, mortality, exterior egg quality, health, integument and the birds use of facilities were registered from 20 until 80 weeks. No effects of group size or keeping system on production or mortality were detected, but the furnished cage gave more cracked and less dirty eggs than the conventional cage. Hens in the furnished cage had better plumage condition, less toe pad hyperkeratosis, shorter claws, less rear body wounds and stronger humerus, but dirtier feet than hens in the conventional cage. Hens in the larger group sizes had the dirtiest feet. In the furnished cage, on average, 86% of all eggs were laid in the nests and 0.6% in the sandbaths. The rolling out efficiency from nests was best in the larger group sizes. During night less than 0.5% of the hens stayed in the sandbath and less than 2% stayed in the nest. Average use of perches was 28% during the day and 91% at night. Hens in the small group sizes used the sandbath most. Dust‐bathing behaviour also occurred on the wire floor.     

Performance of Four Hybrids of Laying Hens in Modified and Conventional Cages

Abstract

In two trials, production, feed consumption, mortality, egg quality and birds' live weight of a total of 2877 caged laying hens of four hybrids, Dekalb XL, Lohmann Selected Leghorn (LSL) and Shaver 288 in Trial 1 and ISA Brown and LSL in Trial 2, were studied during full production cycles. The cage designs were Get-away cages (GA) with 15 hens per cage, a special version of the “Edinburgh modified cage” called “Modified and enriched cage” (ME) with 4 ISA or 5 Leghorn hens per cage, conventional cages of metal (CO) with 4 hens per cage and conventional cages of plastic (PL) with 3 hens per cage. GA and ME included nests, perches and sandbaths. LSL produced significantly better than the other hybrids. Shaver had a significantly lower live weight than Dekalb and LSL, while ISA was significantly heavier than LSL. Production in ME was similar to that in conventional cages and, in Trial 2, birds in ME, CO and PL produced significantly better than those in GA. The highest mortality was registered in GA, where in Trial 2 it was significantly higher than in ME. GA gave a significantly higher and CO a lower proportion of cracked eggs than ME and PL. In both trials ME gave significantly lower proportions of dirty eggs than GA and in Trial 2, the lowest. Few differences between the systems were registered regarding interior egg quality. It was concluded that ME is better for production, mortality and management than GA but similar to conventional cages.     

Behavior, physiology, performance and physical condition of layers in conventional and large furnished cages in a hot environment

The aim of the present study was to compare old layers' level of welfare and performance between conventional and large furnished cages under hot environmental conditions. At the age of 80 weeks, 104 Boris Brown layers were divided into two groups: 12 conventional cages (two hens/cage) and four large furnished cages (20 hens/cage, 240 cm wide × 62 cm deep). The room temperature was set to fluctuate between 25 and 33°C in a day. The hens' behavior, immune response, performance and physical condition were measured. Aggression and moving were more frequent in furnished than in conventional cages (P < 0.05 for both items). Egg production (P < 0.05), egg mass (P < 0.05) and feed conversion ratio (P < 0.01) were better in conventional cages than in furnished cages. No significant differences were found in the birds' immune responses or physical condition between the cage designs. In conclusion, under a hot environment, the performance of old layers in large furnished cages was lower compared with that in small conventional cages, which might be due to their greater aggressive interactions. However, it was not evident that welfare level was lower in large furnished cages compared with conventional cages. Hereafter, additional studies about large furnished cages using young layers over a long term should be performed.     

Bacterial eggshell contamination in conventional cages, furnished cages and aviary housing systems for laying hens

The influence of housing system on the initial bacterial contamination of the eggshell was studied. Two long-term experiments were performed. Bacterial eggshell contamination, as expressed by total count of aerobic and Gram-negative bacteria, was periodically analysed for eggs from a conventional cage, a furnished cage with nest boxes containing artificial turf or grids as nest-floor material and an aviary housing system. Results were log-transformed prior to statistical analyses. For both experiments no systematic differences were found between the conventional cage and furnished cage. The type of nest-floor material in the nest boxes of the furnished cages also did not systematically influence the bacterial contamination. A possible seasonal influence on contamination with a decrease in the winter period (up to > 0.5 log cfu/eggshell) of total count of aerobic and Gram-negative bacteria was observed in the first experiment. The contamination with total aerobic flora was higher (more than 1.0 log) on eggs from the aviary housing system compared to the conventional and the furnished cage systems. For Gram-negative bacteria this was not the case. During the entire period of both experiments, independent of housing system, shell contamination was not influenced by age of hens or period since placing the birds in the houses. For the total count of aerobic bacteria a restricted positive correlation (r2 = 0.66) was found between the concentration of total bacteria in the air of the poultry houses and initial shell contamination.     

Development of furnished cages re‐using conventional cages for laying hens: Behaviour,physical condition and productivity

Furnished cages for laying hens have advantages in allowing normal behaviors and maintaining productivity. As the cost of introduction is a barrier for farms, we developed furnished cages that re‐use conventional cages. To determine the minimum and functional cage design, we compared six designs, combinations of two floor designs (artificial turf or wire cage floor) and three screening designs in the integrated area (no screening, one entrance side or four sides). In total, 144 hens were used, and we measured behavior, physical condition and productivity. Comparing the floors, the percentages of hens performing dust‐bathing and laying eggs in the integrated area were higher in cages with turf than wire floor (P < 0.05 for both). Comparing the screening, dust‐bathing, litter‐exploring and active behavior tended to be more frequent in cages with the integrated area screened on one side than four sides. Feather damage was lower in cages with the integrated area screened on one side than with no screening (P < 0.05). These results suggest that the cage design with an integrated area with artificial turf floor, screened on one side, was effective for furnished cages that re‐use conventional cages.     

Behavior, performance and physical condition of laying hens in conventional and small furnished cages

The aim of the present study was to compare the welfare level and performance of laying hens between conventional and small furnished cages. At the age of 54 weeks, 120 White Leghorn layers were divided into four groups: four (C4) or six hens/cage in conventional cages and four or six (F6) hens/cage in furnished cages. Their behavior, number of steps taken, performance and physical condition were measured. Sham dust‐bathing was greater in conventional cages than in furnished cages (P = 0.05) and dust‐bathing, litter scratching and litter pecking were also observed in furnished cages. Other comfort behavior, moving and number of steps taken were more frequent in the four‐hen cages than in the six‐hen cages (P < 0.01, P < 0.001, P < 0.001, respectively). Though egg production and egg mass in C4 and F6 were lower than in the other groups, no significant differences were found in the other production measurements. Bodyweight gain was larger in the four‐hen cages than the six‐hen cages (P < 0.01). In conclusion, behavior was not restricted in the furnished cages, but activity and bodyweight gain were affected by group size (density) rather than cage design. Hereafter, the studies on suitable density in each cage design, using young layers, are required.     

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

This 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 < 0.05 and P < 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 < 0.05). However, their feed intake and bodyweight did not decrease significantly. Against this decreased aggression, the proportion of birds preening significantly increased (P < 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 < 0.001). The total feather score for all body parts in the birds in furnished cages increased significantly (P < 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.     

Evaluation of the effects of cage height and stocking density on the behaviour of laying hens in furnished cages

1. Limited information is available on how changes in horizontal and vertical space within enriched or furnished layer cages (as defined by Directive 1999/74/EC) influence hen behaviour. This study evaluated the effects of varying minimum cage heights and space allowances on the behaviour of laying hens housed in furnished cages. It was conducted on two flocks of medium brown hybrid hens housed in furnished cages with access to perches and nest boxes on a semi-commercial scale at ADAS Gleadthorpe. 2. Flock 1 consisted of two layer strains (ISA Brown and Babcock 380), housed at two minimum cage heights (38 and 45 cm) and 5 stocking densities between 609 and 870 cm2/bird, with 12 replicates of each of the 20 strain/cage height/stocking density treatment combinations. Stocking density was varied by varying the number of birds per cage from 10 to 7 in standard full-width cages or housing 7 hens in a narrower cage. As a consequence stocking density, group size and trough width per bird co-varied for 4 out of 5 stocking density treatments. 3. Behaviour of flock 1 was sampled at 33 to 36, 46 and 68 weeks of age. At each age one top-tier, one middle-tier and one bottom-tier cage was sampled for each treatment. 4. Few behavioural differences due to cage treatments were detected. Hens at 870 cm2 had shorter feeding bouts than hens at 609 and 762 cm2. Yawning was more common in the cages with greater cage height. 5. Video recordings of flock 1 examined cage height effects on hens' use of vertical space and provided additional data on stretching and self-maintenance activities. No differences in behaviour between 38 and 45 cm cages were found except that scratching head was more common in cages with greater cage height. 6. Flock 2 consisted of two layer strains (Shaver Brown and Hy-Line Brown), housed at 38 and 45 cm and 609, 762 and 1016 cm2/bird, with 18 replicates of each of the 12 strain/cage height/stocking density treatment combinations. Stocking density was varied by housing 10, 8 or 6 hens in standard full-width cages. Behaviour of flock 2 was sampled at 30, 48, 60 and 67 weeks from video recordings. Three cages per treatment from middle-tiers only were sampled at each age. 7. Hens housed at 609 cm2/hen had the longest mean feeding bout, greater than for hens at 762 cm2/hen but not hens at 1016 cm2/hen. More unsuccessful attempts to reach the feeder and sideways and backwards displacements from the feeder occurred at 762 and 609 cm2/hen than at 1016 cm2/hen. A maximum of 8 hens were observed feeding synchronously. 8. These results suggest that changes in horizontal and vertical space over the ranges we studied had little effect on behaviour other than feeding behaviour. Specifying a minimum useable trough space per hen, rather than calculating feeder space from total length of feeder per cage, irrespective of accessibility, might help avoid crowding at the feeder and associated disturbance of feeding bouts.     

Effect of Perches at Different Positions in Conventional Cages for Laying Hens of Two Different Strains

Production, health and behaviour were studied in 648 White Leghorn hens of two strains, LSL and Shaver 288, housed in three-tier battery cages (four hens per cage, 600 cm2 per hen) with three treatments; two with a perch fitted across the cage, 17 (PB) or 24 cm (PC) from the back of the cage, respectively, and control cages without perch (NP). Introducing a perch did not significantly affect production, but PC gave more dirty eggs, and both PC and PB tended to give more cracked eggs. The perch caused inferior keel bone condition and hygiene of the cage floor and a stronger tibia. LSL hens showed higher production, better feed conversion ratio, fewer cracked eggs, better keel bone health and shorter claws than Shavers. Use of the perch averaged 25 and 90% during day and night, respectively. The perch did not significantly affect other behaviours. There were significant interactions between strain and cage design regarding laying percentage, egg weight, cracked eggs, live weight, foot- and perch hygiene, keel bone condition and toe pad hyperkeratosis.     

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

The 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 < 0.1) and nest box less (P < 0.01) than subordinate birds did. The use of the nest box decreased for subordinate birds from 57 to 67 weeks of age (P < 0.05). The dominant birds performed aggression and exploring more frequently than the subordinate birds (P < 0.001 and P < 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 < 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 < 0.1 and P < 0.05, respectively). Aggression decreased for dominant birds from 57 to 67 weeks of age. In contrast, eating (P < 0.1) as well as drinking (P < 0.1) and other comfort behaviors (P < 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.     

Effect of production system and flock age on egg quality and total bacterial load in commercial laying hens

The shell of the egg is essential in providing shape to the egg and ensuring safe packaging of the internal contents; however, shell defects have been shown to increase the risk of microbial contamination of eggs. Eggs were collected from commercial cage and free-range flocks at the ages of 25, 35, 45, 55, 65, and 75 wk. From each collection per flock, 30 eggs were processed for the eggshell and egg internal quality determination, 30 eggs for cuticle estimation, 30 eggs for mammillary layer ultrastructural features scoring, and 60 eggs for egg microbial enumeration. Translucency score and shell reflectivity were significantly higher in free-range eggs and increased with flock age in both production systems. Egg weight, shell weight, percentage shell, shell thickness, albumen height, Haugh unit, and yolk color were higher for cage eggs. The amount of cuticle was higher in cage eggs and fluctuated with flock age in both production systems. For the mammillary layer ultrastructural variables, a significant effect of production system and flock age was observed for early fusion, Type A bodies, and Type B bodies, whereas aragonite, depression, erosion, and hole were rarely observed. Variability of mammillary cap size, the incidence of poor mammillary cap quality, incidence of late fusion, alignment, Type A bodies, Type B bodies, and cubic cone formation were greater in the free-range versus cage system and increased with flock age in both production systems. The incidence of confluence and early fusion were greater in cage eggs and decreased with age in both production systems. Significantly lower total microbial load was observed for cage compared with free-range eggs, but the overall bacterial load recorded in this study was low. It can be concluded that cage eggs were better in overall quality when directly compared with free-range eggs.     

Effect of Feed Structure on Performance and Welfare in Laying Hens Housed in Conventional and Furnished Cages

A small-scale experiment was conducted to examine layers' selection pattern of whole wheat (WW), protein concentrate (PC) and coarse shell meal (SM) throughout the light day. Consumption of all feed components increased prior to darkness. However, an interaction between SM and the other feed components was found (P<0.05), caused by a greater increase in SM consumption prior to darkness than WW and PC. This interaction is probably related to the requirement for calcium for eggshell formation. Energy (WW)/ Protein (PC) consumption ratio did not vary throughout the light day. In a large-scale experiment, a diet with 40% whole wheat incorporated into 3 mm pellets was compared with a complete diet, also as 3 mm pellets, but containing no whole wheat. Coarse shell meal was added in the feed trough for the experimental diet. These diets were examined in conventional 3-hens cages and two furnished cage systems. The hybrids LSL and Shaver 2000 were used. A tendency towards a lower (P=0.07) feed conversion ratio (FCR) was found in the experimental diet relative to the control diet. This may be a result of a better plumage condition for birds fed the experimental diet. Weight of gizzard and gizzard contents was higher among birds on the experimental diet. Self-selection of shell meal did not affect eggshell strength and legbone strength. Birds housed in furnished cages with 16 birds per cage unit showed higher (P<0.05) feed consumption than birds housed in furnished cages with 8 hens per cage and birds housed in conventional 3-hens cages. Egg production was similar in all cage systems, except for a tendency for lower (P=0.06) egg production in the 8-hens cages in the second half of the experiment period. Plumage condition was generally poorer (P<0.05) in the furnished cages than in the conventional 3-hens cages. Fewer comb lesions were found among birds in furnished cages, which may indicate less aggression in layers housed in furnished cages compared with conventional barren 3-hens hen cages.     

Effect of furnished small group housing systems and furnished cages on mortality and causes of death in two layer strains

1. Mortality and causes of death were recorded over two trials with 13045 Lohmann Selected Leghorn (LSL, white layer strain) and 4410 Lohmann Brown (LB) laying hens kept in furnished small group housing systems and furnished cages. In trial 1, hens were housed from weeks 19 to 71 (LSL) and 17 to 69 (LB). In trial 2, LSL hens were housed from weeks 18 to 57. 2. The hens were kept in groups of 40 and 60 in the furnished small group housing system Eurovent 625 + a-EU and in groups of 10 and 20 in the furnished cages Aviplus and Eurovent 625A-EU. 3. To investigate the possible effect on mortality of rearing the birds on litter floors or in cages, in trial 2 half of the LSL hens were reared on the floor and half in conventional cages. 4. Mortality was greater in the Eurovent furnished small group housing system (5.2%) than in the furnished cages Aviplus (4.0%) and Eurovent (4.2%). 5. Mortality was also affected by the interactions among housing system and trial, layer strain and rearing. In trial 1, more LB laying hens died in the Aviplus system than in the Eurovent group system. There was no significant difference in mortality of the LSL laying hens between housing systems in trial 1. In trial 2, mortality of the LSL hens was greater in the group housing system (hens reared on litter floors: 10.1%; hens reared in cages: 2.8%) than in the furnished cage Aviplus (hens reared on litter floors: 6.0%; hens reared in cages: 1.5%). 6. Mortality was greater in floor-reared LSL laying hens than in the LSL laying hens reared in conventional cages. 7. Group size within housing system had no significant effect on mortality. 8. The most common findings at autopsy were different types of cannibalism (65.51%), with vent cannibalism (38.57%) the most common.     

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 x 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.     

Factors affecting the use of perches in cages by laying hens

1. Three experiments were carried out with ISA Brown laying hens housed in individual cages with softwood perches of rectangular cross section fitted across the width of each cage, to investigate factors affecting the tendency of hens to lay their eggs from the perches and to use perches at other times. These factors were perch width and angle and method of perch introduction. 2. In experiment 1 there were 4 treatments. Perches were 38 or 60 mm wide; half of each width were flat and half were fixed at 8 , parallel to the slope of the floor. In 2 similar trials (with 48 and 44 birds respectively, equally divided between treatments) birds were moved to experimental cages already fitted with perches. Birds with 38 mm, sloping perches laid less than one third of their eggs from the perch (31% and 9% in the two trials) while those with the other designs laid more than 80% from the perch. Narrow sloping perches were not otherwise aversive and there was no consistent variation between treatments in total time perching. 3. In experiment 2, 32 birds were allowed to start laying on the floor of the experimental cages then perches were introduced at 24 weeks with 8 birds on each of 4 treatments: 50 mm perches fixed flat and 38 mm perches fixed flat, and at 5 and 10 respectively. Only 27% of eggs were laid from the perches with no variation between treatments either in this behaviour or in total time perching. 4. Experiment 3 provided 24 of the birds from experiment 2 with double-length perches to determine whether they showed preferences for the design features under consideration. Either half the perch length was flat and half sloping at 10 or half was 38 and half 50 mm wide. Again a relatively low proportion of eggs was laid from the perches (18%) and birds showed no significant preference for different perch designs as indicated by either how much they perched or where they perched. 5. These results suggest that both perch design and the way pullets are introduced to perches influence the proportion of perch-laid eggs. They confirm that in some circumstances laying from perches can be a serious problem, but that in other circumstances incidence can be reduced to a manageable frequency. Perches may therefore be practical in commercial production without increasing the number of cracked eggs. The results are also likely to be applicable in cages with other facilities including nest boxes.     

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

A 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 < 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 < 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 < 0.01), and the use of tiered wire floors with feeders accompanied this (P < 0.01). Comfort behaviors, including dust bathing, were noted less in the aviary than in the furnished cages throughout the observation period (both P < 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 dietary protein on egg production of laying hens housed in furnished or conventional cages

Abstract

In the present experiment the effects of dietary protein content on egg production of hens kept either in conventional cages (CCs) or furnished cages (FCs) were studied. A total of 1088 LSL (Lohmann LSL-Classic Layer) hens were housed in either FCs or CCs and offered high or low protein diets with a protein/energy ratio of 17 or 13, respectively, during three consecutive feeding phases of 20, 16 and 16 weeks, respectively. There was no interaction between the effects of cage design and of dietary treatment on laying performance. Hens kept in FCs consumed less feed than hens in CCs (p<0.05). After the first feeding phase, hens housed in FCs produced fewer eggs (p<0.01) than hens in CCs. No differences in the feed conversion ratio were found between the housing systems. Hens on the low protein diet laid smaller eggs than hens on the high protein diet (p<0.001). No effect of dietary protein on laying rate was found. It can be concluded that dietary protein affects egg production irrespective of the cage type.