Perch length in cages for medium hybrid laying hens

1. ISA Brown hens were housed as groups of 4 from 18 to 72 weeks in 24 cages 450 mm deep, each with a softwood perch of rectangular cross‐section fitted across the rear. There were 4 treatments, each with 6 cages: cage widths and perch lengths were 480, 520, 560 or 600 mm.

2. Daytime perching did not differ significantly between the treatments. At night, over the whole year, 81% of birds in the 480 mm cages and 86% in the 520 mm cages roosted on the perch. This figure reached about 95% in the 560 and 600 mm cages, significantly more at most ages than in the 480 mm cages.

3. Feather damage was slightly less, but claw problems slightly more, in the 2 wider treatments than in the 2 narrower treatments. Birds in the wider cages were calmer when approached or handled by humans than those in the narrower cages. This may have been associated with variation in space allowance between the treatments.

4. There was a trend for lower production in the 480 mm cages than in the other treatments which may have been associated with the reduced feeding space in this treatment. There were few other treatment differences in production traits.

5. The balance of the evidence from this study is that when perches are provided in laying cages for medium weight hybrids, 140 mm of perch space per hen is adequate. For the amelioration of a number of the welfare problems of conventional cages, provision of perches should be combined with other modifications.     

Diurnal patterns of feeding and activity in laying hens in relation to dietary restriction and cage shape

1. The diurnal feeding pattern and motor activity of medium‐weight hybrid hens housed in groups of four were observed. Cages of two shapes were compared: conventional deep cages (406 × 457 mm) and shallow cages (610 × 305 mm).

2. Birds in conventional deep cages were more active than those in shallow cages in each of four different periods of day. Activity reached a peak between 11.00 and 13.00 h irrespective of cage shape.

3. Mean feeding activity was greater in the shallow (45.6%) than in the conventional deep cages (39.9%).

4. Mean feeding activity was greater in birds fed ad libitum (43.3%) than in those fed on a restricted diet (40.4%).

5. Although restricted birds in shallow cages showed more feeding activity than those in conventional deep cages they consumed less food (56% against 67%) in the 7 h between supply of their daily ration and the onset of the dark period.

6. Feather damage was greater in the conventional deep cages than in the shallow cages.

7. The more efficient utilisation of food by hens in shallow cages is probably due largely to three factors: reduced levels of motor activity and general disturbance, a more leisurely eating pattern and better feather cover.     

Ability of laying hens to negotiate horizontal perches at different heights,separated by different angles

1. This paper describes how birds move between horizontal perches at different heights with different angles separating them, using the time to complete the task and the number of birds failing to indicate ability.

2. For the first experiment, 4 groups of 15 birds (ISA Brown) were subjected to each of the experimental treatments (using three perches with angles of 0° (horizontal control), 30°, 45° or 60° between them). The birds were required to move upward between the perches for each treatment and then to move downward between the perches, as a second part of the experiment.

3. Birds moving up between the perches took significantly longer at 60° than at any other angle. No birds failed to complete the task.

4. For birds moving downward between the perches, the median time to complete the task increased significandy with angle. Furthermore, the number of birds failing to complete the task increased with angle.

5. A second experiment was conducted to test whether the vertical or horizontal component of distance affected birds’ ability to negotiate perches separated by different angles.

6. For the second experiment 4 groups of 10 Lohmann Brown laying hens were subjected to each of the following treatments: two horizontal perches separated by 30° or 60° and either direcdy, horizontally or vertically separated by a set distance of 50 cm. Birds were required to move both up and down between perches.

7. Birds negotiated horizontally‐separated perches more successfully at 30° than at 60°. However, when the vertical distance between the perches was 50 cm there was no significant difference in the ability of birds to move downward at 30° or 60°. For birds moving upward, 60° was easier to negotiate dian 30°.

8. The vertical and horizontal separations, as well as the different angles affected the ability of birds to move between perches. There was a general decreasing trend in ability with increasing vertical separation between perches.

9. The findings are important in terms of arrangements of perches to improve bird welfare. To minimise die risk of injury, the angle between perches at different heights should be no more than 45 degrees, and die horizontal and vertical distances between these perches minimised, to allow the birds to be able to move downwards more easily.     

Nesting,dust bathing and perching by laying hens in cages: Effects of design on behaviour and welfare

1. Laying hens (192 ISA Brown medium hybrids) were housed from 18 to 72 weeks as groups of 4 in conventional or experimental cages. The main area of all cages provided 675 cmVhen. All experimental cages had perches, dust baths and nest boxes, which were of three types: litter (L), artificial turf (A) or plastic rollaway (P). These facilities provided an additional 375 to 480 cm²/hen. The nest boxes and dust baths occupied either high or low positions. Behaviour, physical condition and production of the birds were regularly recorded.

2. Mortality was low (1.6% overall) and egg production very good in all treatments. The proportion of cracked and dirty eggs was slightly (but not significantly) higher in the experimental cages. In the experimental cages 90% of eggs were laid overall in the nest boxes and 3% in the dust baths. The proportion laid in the nest boxes was lower early in the laying cycle and increased with time, reaching 99% in A.

3. The facilities were heavily used. Birds spent about 25% of day time on the perches and 10–15% in or near the nest box and dust bath. At night, the majority of birds (90 to 94%) roosted on perches, but most of the remainder were on the lips of the nest box or dust bath, fouling the interiors.

4. Pre‐laying behaviour was much more settled in the experimental cages (45 min spent in the eventual laying position) than in the conventional ones (20 min) and total duration varied from 68 min in A to 87 min in P. The number of nest entries varied from 3.0 (A and P) to 4.3 (L); disturbance to sitting birds was correspondingly greater in L.

5. Dust bathing in the experimental cages generally took place during the afternoon in a single bout of about 5 min duration, whereas in the conventional cages it was brief and fragmented (3 bouts of 10 s each). The dust bath was also used for foraging behaviour (pecking and scratching). The treatments with small dust baths (A and P) caused problems for the birds.

6. Feather, foot and claw damage all tended to be less in the experimental than in the conventional cages, though only in the last case was the difference significant. Keel bone depressions appeared to be associated with perches; they were present in 43% of hens in the experimental cages but only 4% in conventional cages. There were no significant differences in body weight or in tibial or humerus strength between birds in the various treatments.

7. This study confirms that experimental cages with nest boxes, dust baths and perches offer appreciable benefits for welfare, with few production problems. The most successful treatment (A) could, with relatively minor modifications, form the basis of a practical design for large-scale commercial production.     

Battery cage shape: Its effect on diurnal feeding pattern,egg shell cracking and feather pecking

1. Battery cages 460 mm in depth (deep) were compared with 305 mm cages (shallow); the two shapes provided equal areas per bird.

2. More eggs were produced per hen housed from 30 to 70 weeks in the shallow cages; the difference approached significance.

3. The pattern of feeding activity over the day was significantly more U‐shaped in the shallow cages; this pattern accords more closely with physiological requirements.

4. Feather damage caused by pecking was slightly but significantly more severe in the deep cages at 70 weeks.

5. The proportion of cracked eggs (collected from 60 to 70 weeks) was significantly lower in the shallow cages.

6. The arrangement of the hens was such that within the shallow cages a higher proportion of birds was present in the front half.

7. It is suggested that some of the advantages conferred by the shallow cage may be related to the greater accessibility of the food trough.     

Analysis of landing behaviour of three layer lines on different perch designs

1. The prevalence of keel bone deformities in laying hens is high and is partly associated with unsuitable perch designs, which impose a risk of injury due to an unstable footing.

2. Over two experiments, 9 or 10 hens of each of three layer lines (Lohmann Selected Leghorn (LSL), Lohmann Tradition (LT) and Lohmann Brown (LB)) were filmed while landing on three different perch types, including steel perches of various diameters, a commercial mushroom-shaped plastic perch and a newly developed prototype perch with a soft surface material.

3. Data on landing behaviour (safe vs. unsafe or failed landing) following downward jumps were collected for 25, 50 and 60 cm vertical distances and 75 cm horizontal distance between a wooden start perch and the different destination perches.

4. The highest proportion of safe landings occurred on the prototype perch, whereas least safe landings were observed on steel perches, irrespective of their diameter. The mushroom-shaped perch was intermediate with regard to the safeness of landing.

5. A threshold of 50 cm vertical distance (34° slope) was identified as the optimum for downward jumps on perches in order to reduce the risk of unsafe or failed landings. Above this threshold, the proportion of safe landings declined significantly.

6. Brown shell layer types (LB and LT) had a lower proportion of safe landings compared to the white shell layer type (LSL), whereas no difference was found between LB and LT layer lines.

7. Although steel perches prevail in commercial housing, these perches were found to be least advantageous with regard to landing behaviour. The prototype perch provided the most stable footing on perching and is a promising alternative to replace commercial steel perches, thus helping to reduce the risk of perch-related keel bone injury.     

The use of perches by broilers in floor pens

1. Small flocks of broilers, numbering between 160 and 240, were placed in two deep‐litter pens each 10.13 m² in area, one of which contained four perches each 3.05 m long and about 0.3 m above the floor. The presence of birds on the perches was noted. Body weights at 56 d were recorded and food intakes from 0 to 56 d measured.

2. In experiments 1 and 2, when 160 birds without perches were compared with 240 with perches, the latter gained slightly less weight but had an improved food conversion efficiency. At 8 weeks about 27% of the birds were observed on the perches at any one time.

3. In experiments 3 and 4 both pens contained about 200 birds. Those with perches gained slightly more weight and food conversion efficiencies were similar. At 8 weeks about 12% of the birds were observed on the perches.

4. Perch usage appeared to be governed both by the age and size of the birds and by their density. In all four experiments the numbers perching at 8 weeks seemed to be such that the density of birds on the floor was about 17 birds/m² (28 to 34 kg/m²).     

Feather damage in hens caged individually

1. The plumage of hens housed singly in cages was generally in good condition after one year. There was slightly more feather loss where hens could peck their neighbours’ plumage (adjacent cages) than where this was not possible (spaced cages).

2. It was concluded that most, though not all, of the feather damage seen in the individually‐caged birds was due to abrasion, but that abrasion was likely to be relatively unimportant in multi‐bird cages.

3. There were no significant differences in egg production or food intake associated with the two kinds of housing.

4. In the adjacent cages there was an increase in maintenance requirement related to increased feather damage, which amounted to about 7% for an increase of about one unit in feather‐loss score. In the spaced cages the increase was less.

5. Hens with increased feather damage also showed increased egg production.     

Performance of a deep litter system for egg production

1. Medium hybrid hens were housed from 20 to 64 weeks in a deep litter house as flocks of 300, 370 and 370 and at stocking densities of 2–4 to 10–7 birds/m² in three successive laying cycles. Sister birds were housed in cages in an adjacent building as groups of 3 and 4, at 750 or 560 cm²/bird.

2. Hen housed egg production was lower on litter (208 to 235) than in cages (230 to 253). However, the estimated 52‐week values for litter were comparable to or better than standards published by the National Farmers’ Union.

3. Ambient temperatures were well controlled in both houses, but atmospheric dust and ammonia were a problem in the litter system and ammonia was a problem in the deep pit cage house. Litter condition was good at all stocking densities.

4. There was a trend for production to increase with stocking density on litter, but to decrease in cages.

5. Most egg quality variables were similar in the two systems, although there were more dirty eggs from litter and shell thickness was slightly greater in eggs from cages.

6. Body weight increase was initially faster in birds on litter; caged hens were equally heavy by the end of lay, but a greater proportion of their body mass was lipid.

7. The severity of feather damage and loss was correlated with stocking density for hens both on litter and in cages, being worse at the higher densities. Median cage scores were greater than values from litter at low densities but less than those from high densities. Beak trimming reduced feather damage on litter but had no effect in cages.

8. Mortality was low (1 to 3%) for all flocks, except those in year 3 which had not been beak trimmed and which suffered from cannibalism both in cages and on litter.     

Behaviour,health and integument of four hybrids of laying hens in modified and conventional cages

1. In 2 trials the health and behaviour of a total of 3552 caged laying hens of 4 hybrids, Dekalb XL, Lohmann Selected Leghorn (LSL) and Shaver 288 in trial 1 and ISA Brown and LSL in trial 2, were studied. 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 metal cages with 4 hens per cage without (CO) and with a perch (PC) and conventional plastic cages (PL) with three hens per cage. GA and ME included nests, perches and sandbaths.

2. In the first trial two nest models were used, artificial turf and welded wire floor. In the second trial both nest models were used in GA, while all nests in ME were equipped with artificial turf. In the second trial there were 4 sandbath treatments in ME; no sandbath, sandbath (25×50 cm) first opened at 16 weeks of age, sandbath first opened at 26 weeks and double size sandbath (50 × 50 cm) first opened at 16 weeks. Hens in GA were allowed access to the sandbaths from 26 weeks.

3. At 35 and 55 weeks the best plumage condition (feather cover) was found in PL and GA but plumage condition in ME was not significantly inferior than in GA. Hens in GA had the dirtiest plumage and most bumble foot but no toe pad hyperkeratosis. Some toe pad hyperkeratosis occurred in the other systems. Most keel bone lesions were found in systems with perches. The highest mortality was registered in GA. Hens in systems with perches, sandbaths and nests had increased strength of humerus at slaughter.

4. More eggs were laid in nests with artificial turf than in welded wire floor nests. LSL hens laid larger proportions of eggs in the nests (94% and 92% in the two trials) than the other hybrids. Less than 1% of the eggs in ME and 2% in GA were laid in the sandbaths.

5. The use of perches in ME and PC was approximately 30% in the day time. At night the use was 93% in ME and 89% in PC in trial 1 and 96% in ME and 81% in PC in trial 2.

6. Hens in ME with the double sized sandbath both visited the sandbath and performed dust bathing behaviour most, followed by hens in GA, hens in ME with access to the bath from 16 weeks and last, hens in ME with access to the bath from 26 weeks.

7. It is concluded that enrichments of laying cages are used by the hens to a large     

Influence of stocking density and layer age on production traits and egg quality in Japanese quail

1. Japanese quail hens were housed from 6 to 26 weeks of age in cages providing areas of 150, 180, 210 and 240 cm²/bird.

2. Body weight gain, age at 50% egg production, mortality, hen‐day egg production and food conversion values showed significant improvement with proportionate increase in cage space per layer.

3. Egg weight gradually increased with age but shell thickness was influenced neither by age of the hen nor by stocking density.

4. Yolk index and colour were superior in the lowest stocking density (more cage space) group; other egg quality traits and egg weight were not influenced by stocking density.

5. The albumen index, internal quality unit, yolk index and yolk colour values increased with age.     

Factors influencing bacterial eggshell contamination in conventional cages,furnished cages and free-range systems for laying hens under commercial conditions

1.?The aim was to assess eggshell contamination in various laying hen-housing systems and to identify factors influencing this contamination.

2.?Fifty-eight laying hen farms in France were studied, including 21 flocks housed in conventional cages, 7 in furnished cages and 30 kept on-floor.

3.?Sixty eggs per flock were analysed to obtain counts of the total mesophilic flora. Data on equipment and hen management were collected.

4.?Mean bacterial count on eggshells tended to be higher in on-floor systems (4·82 ± 0·51 log CFU/eggshell) than in cage systems (4·57 ± 0·58 log CFU/eggshell, P = 0·09).

5.?Contamination increased with age of the hens, airborne dust concentration, manual packing of the eggs, and packing in plastic rather than in recycled-pulp egg-flats.

6.?The effect of the housing system on eggshell contamination, previously described in experimental assays, was confirmed under production conditions.     

Traits influencing the hatching performance of Japanese quail eggs

1. Japanese quail eggs from moderately heavier sires showed superior fertility; while fertile eggs from moderately heavier dams hatched slightly better than the eggs from lighter dams.

2. Higher rates of fertility and hatchability of Japanese quail eggs were observed from parents of 10 to 19 weeks of age, with peak fertility and hatchability at 14 and 12 weeks of age, respectively.

3. Sex ratios of 1:2 to 1:5 gave comparable fertility and hatchability results.

4. The hatching performance of quail eggs from cage and deep litter reared breeders was comparable.

5. Fertility and hatchability were directly proportional to the egg weight.

6. Quail egg shell colour, tints and blotches were found to influence hatching performance.

7. Storing quail eggs at 16 ± 2°C and 75 ± 5% relative humidity for more than 4 d reduced hatchability.

8. Hatchability of eggs stored at room temperature was improved if they were sealed in polyethylene bags.

9. Provision of light during the first 14 d of incubation resulted in a photo‐acceleration of about 3.2 h.     

Effects of cage shape,colony size,floor area and cannibalism preventatives on laying performance

1. Wire cages of variable width and depth, with a floor slope of 1 : 12, were used in two experiments to study the effects of cage depth, feeding space (= cage width), floor area, colony size and two methods of controlling cannibalism in White Leghorn x Australorp laying hens.

2. The least floor area (0.035 m²/bird) depressed production in two‐bird cages. Floor area had little effect on the performance of larger colonies.

3. Birds in colonies of three, four or six laid and survived equally well when feeding space/bird and floor area/bird were constant.

4. Production per hen d and food intake were higher, but return on estimated capital outlay was lower, with 102 mm than with 76 mm feeding space/bird when colony size and floor area/bird were constant.

5. Production and food intake of birds which were not treated to prevent cannibalism declined, and mortality increased, as cage depth increased from 385 to 915 mm concomitantly with increasing colony size from 2 to 7 birds and decreasing feeding space from 152 to 43 mm/bird.

6. Increasing cage depth did not increase the proportion of cracked eggs.

7. Mortality was higher among birds fitted with plastic spectacles than among debeaked birds.     

Metabolic and anatomical adaptations of light‐bodied chicks to intermittent feeding

1. Chicks of a light‐bodied strain were deprived of food on alternate days from 15 to 46 d of age.

2. Hyperphagia, amounting to twice the intake of control birds early in the experiment, occurred on the repletion day.

3. Final body weight attained 80% of that of the controls.

4. Body fat concentration decreased at first but returned to that of controls after 3 weeks.

5. A consistent hyperlipaemia was observed after food deprivation or restoration.

6. There was a marked increase in the digestive enzymes found in the small intestine, but not in the pancreas during the repletion day.

7. These responses may be considered as mechanisms to reduce the physiological manifestations of starvation.     

Nesting and dust bathing by hens in cages: Matching and mis‐matching between behaviour and environment

1. Medium hybrid hens were housed as groups of 4 at 18 weeks of age in cages of 4 different types: control battery cages allowing 675 cm2/bird; similar cages with a rear‐mounted dust bath, 290×345×240 mm, containing sand (D); cages with a rear‐mounted nest box of the same size, containing wood shavings (N); cages with both (DN). In half the experimental cages access to nests was restricted to the morning and access to baths was restricted to the afternoon, by automatic sliding doors.

2. During the first 24 weeks of lay about 95% of eggs were laid in nest boxes in treatments N and DN. Slightly fewer were laid in boxes where doors were present. Over 90% were laid in dust baths in D cages without doors and 67% with doors, which birds learned to open. Prelaying behaviour was least disturbed in nest boxes, most disturbed on the floor and intermediate in dust baths.

3. Fully developed dust bathing occurred in D and DN as bouts lasting 5 to 10 minutes; its incidence, surprisingly, was greater when doors were present and greater still when nest boxes were present, even though it was not performed in them. It was also performed by some hens in nest boxes in N (without doors). In N with doors and in control cages, dust bathing occurred on the bare floor in truncated form, as serial bouts each lasting only about 10 s. This truncated dust bathing was also occasionally observed in D and DN.

4. Plumage, foot and claw damage were less in hens from modified cages than from controls. Egg production was very good in all treatments but more eggs from control cages were downgraded because they were dirty or cracked.

5. When a choice was available birds generally partitioned their behaviour appropriately between nest box and dust bath. In N and DN virtually all prelaying and nesting behaviour took place in the nest boxes. Matching between dust bathing and the environment was less close; the reasons for its relatively low incidence and occurrence in truncated form outside dust baths remain to be established.     

Bone structure and breaking strength in laying hens housed in different husbandry systems

1. Bone structure and breaking strength were measured in hens that had been housed throughout a laying year in battery cages or in Perchery, Naturel or Litter and Wire husbandry systems.

2. Battery caged hens had the poorest bones, as assessed by measurements of cancellous bone volume, radiographic density, cortical thickness and three‐point breaking strength.

3. Humeri from birds in the Litter and Wire system were less dense radiographically and weaker than those from Perchery or Naturel birds but leg bone characteristics were similar with these three systems.

4. There were no differences in bone characteristics between birds in Perchery and Naturel systems.

5. There were strong correlations between radiographic densities and strengths of contralateral humeri and tibiae over all husbandry systems. Humerus structural and strength characteristics may be the best criteria of osteoporosis in hens.

6. It is concluded that the extent of movement allowed by different husbandry systems affects structural bone loss and bone strength in laying hens.

7. It is further concluded that the breaking strength of a hen's bone is closely related to morphometric measures and radiographic density of its structural components.     

The Edinburgh modified gage for laying hens

1. Behaviour, production and welfare of ISA Brown medium hybrids were assessed in 2 trials (each from 20 to 44 weeks of age) of a novel design of cage for laying hens: the Edinburgh Modified Cage (EMC).

2. The EMC was 600 mm wide, 450 mm deep and 450 mm high at the rear; it had a softwood perch and at one side a 250 mm wide nest box (containing litter or artificial turf) with a dust bath direcdy above. It housed 4 birds and provided 675 cm^2/bird in the main cage with an additional 281 cm² /bird in the nest box. The nest box and dust bath had automatically controlled doors which were closed at night. There were 18 EMC; in the first trial these were compared with 6 control cages with perch but without next box or dust bath.

3. Hens spent 32 to 37% of day time on the perch, 5 to 7% in the dust bath and 5 to 6% in the nest. At night 92 to 98% roosted on the perch.

4. Initially only 55 to 70% of eggs were laid in the nest box partly because some eggs were laid before dawn. Once the door was retimed to open 3h before lights‐on the proportion rose to 91 to 96%. Very few eggs were laid in the dust bath. Pre‐laying behaviour lasted longer in treatments with nest boxes (55 to 76min) than in control cages (48min); disturbance was slight in all treatments, but lowest in control cages.

5. Dust baths were well used, with on average 61% of hens dust bathing during a 3‐h afternoon observation period compared with only 17% in control cages. Two birds could use the dust bath simultaneously.

6. It was concluded that although a number of minor design features still required attention the EMC has potential to reduce the disadvantages of conventional cages for welfare while retaining their advantages and has possible commercial application.     

Genotypic differences in speed and magnitude of response to ahemeral lighting

1. The paper compares between three genetically different lines in their egg weight and shell thickness response to a 28‐h cycle.

2. The response in shell thickness to ahemeral lighting was more rapid (2.2 d) than for egg weight (4.2 d).

3. Differences between genotypes were evident in both the speed and magnitude of response.

4. Overall, egg weight and shell thickness on the 28‐h cycle were 7% and 8% greater than on 24 h.

5. The allometric increase indicates that the increase in shell weight was on average 14% more than the increase in egg weight.     

Effects of group size on the feeding behaviour and growth of chicks

1. The aim of the study was to see if social facilitation of feeding has a lasting effect on the growth of chicks.

2. In two experiments, newly hatched hybrid and Brown Leghorn chicks were reared in isolation and in small groups of different sizes, and their growth, food intake and feeding activity were measured for several eeks.

3. Initially, chicks of both strains grew faster when they were grouped than when they were in isolation, as a result of a more efficient conversion of food rather than as a result of increased consumption.

4. Later, chicks in the largest groups converted their food less efficiently, possibly because of increased disturbance.

5. From 6 to 12 weeks, when the chicks were in larger cages, growth rate was not affected by group size, but food intake and food conversion were affected differently in the two strains.

6. In general, the isolated chicks ate about the same amount as the grouped ones, and it is doubtful whether social facilitation of feeding occurred at all in these experiments.