Effects of relocation on production in caged layers

1. Two experiments were conducted to determine the effects on laying performance of relocating caged hens at 30, 42 and 54 weeks of age.

2. In experiment 1 with hens caged individually, treatment groups comprised relocated hens given 5 new neighbours and hens not relocated but given 0, 2 or 4 new neighbours.

3. In experiment 2 with hens housed two per cage, treatment groups comprised relocation with or without that hen which shared the cage before the move.

4. In both experiments relocated hens laid fewer eggs in the week following social reorganisation.

5. Relocated hens in experiment 1 ate less food in the week following the shift at 42 weeks of age than did hens not moved. In experiment 2 in which all hens were moved, food consumption was not affected.     

Influence of front curtain design on nest choice by laying hens

1. The aim of this study was to investigate the effect of front curtains, one-piece (OP) or sliced in stripes (SL), on the hens’ nest preference and laying behaviour in an aviary system. We predicted that hens prefer SL-nests as they could perform nest inspections and enter and leave the nest along its whole width leading to fewer conflicts and more settled laying behaviour.

2. Eight pens containing 20 White Leghorn laying hens were equipped with two roll-away nests, one with OP and one with SL curtains. Laying behaviour was recorded for two days at peak lay in weeks 25 and 26.

3. More nest visits and more nest entries and exits along the whole width of the nest were counted in SL-nests. More sitting events without egg laying were performed in the OP-nests. No differences were found in the number of hens visiting the nests, egg number or aggressive behaviour.

4. Hens appeared to value the seclusion and protection provided by a closed front curtain. However, sliced curtains provided more opportunities to perform nest inspections.     

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.     

Effect of substrate provision on performance and behaviour of laying hens in the pecking and scratching area of furnished cages

1. An experiment was set up to study the effects of substrate provision on performance and behaviour in the pecking and scratching area (PSA) of non-beak-trimmed hens housed in large furnished cages (60 hens/cage).

2. Three layer hybrids (two brown and one white, ISA-Hendrix Genetics, France) and two substrate conditions (with or without wheat bran automatically distributed on the PSA) were compared in a 3 × 2 experimental design with 12 cages per treatment.

3. Substrate distribution improved laying rate with no impact on the frequency of dirty or cracked eggs.

4. Substrate distribution improved the viability and body integrity of hens, which were not beak-trimmed.

5. Distribution of substrate tended to increase the number of hens in the PSA and enhanced their pecking and scratching behaviours but had a negative impact on the number of dust bath bouts per cage and encouraged dust bathing on the wire floor close to the feeder.

6. The white hens laid more eggs in the nest than the brown birds and used the PSA more for pecking, scratching and dust bathing at the end of the day than the brown hens, underlining the necessity to adapt cage furnishing and rearing management to specific behaviours of each layer genotype.     

Effect of body weight loss and feeding regimen on the performance of moulted breeder layers

1. The effects of body weight loss (0.20, 0.25 or 0–30) during the period of food withdrawal and the subsequent feeding of cracked grain for 3 weeks, pullet grower ration for 3 weeks or layer ration immediately after the period of food withdrawal and their interactions on the second cycle performance of breeder layers were investigated.

2. Hens losing 0.30 of their initial body weight (BWL) produced more hatching eggs and chicks than those which lost 0.20 BW.

3. Hens fed on cracked grain produced fewest non‐hatching eggs, most chicks and the most efficient food utilisation.

4. The interactions showed that hens which lost 0.20 BW and were fed on layers ration produced most eggs. When number of chicks hatching was the criterion then hens losing 0.25 to 0.30 BW which were fed on cracked grain for 3 weeks gave the best performance.     

Nest box design and nesting material in a deep litter house for laying hens

1. Preferences of hens for different types of nest box were tested in two deep litter pens, each containing 300 Isabrown laying hens. Four types were offered: traditional wooden nests with litter, metal rollaway nests with plastic liners, wooden rollaway nests with artificial turf and autonests.

2. Most eggs were laid in traditional nests (70% in pen 1, 66% in pen 2). Metal rollaways were the next preferred type. These preferences were confirmed by analysis of records from individual nest boxes, and by observations of hens marked with wing tags.

3. Choice of nesting material was tested in one pen of 370 hens. Traditional nests were provided, containing either wood shavings or a mixture of buckwheat and oat husks.

4. Preferences for type of nesting material were equivocal. The majority of eggs were laid on wood shavings initially, but on buckwheat/oat husks later. Individual hens were inconsistent in their choice. A deep (100 mm) layer of nesting material was preferred to a shallow (25 mm) layer.

5. Individual, wooden nest boxes incorporating buckwheat/oat husk nesting material on a movable belt are probably the most suitable system for automation of egg collection in deep litter houses.     

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.     

Studies on effects of nutritional factors on bone structure and osteoporosis in laying hens

1. A modern hybrid strain of laying hen (Hisex) was fed from point of lay to 68 weeks on a control diet and diets containing oystershell, fluoride, 1,25‐dihydroxycholecalciferol, ascorbic acid, a lower concentration of phosphorus and a combination of a lower concentration of crude protein and higher concentration of vitamin K. Hens from a much older strain (Brown Leghorn J‐line) were fed on the control diet.

2. Plasma variables were measured during lay. End‐of‐lay trabecular and medullary bone volumes in the proximal tarsometatarsus and free thoracic vertebra were measured by histomorphometry.

3. The majority of Hisex hens were considered to be osteoporotic by the end of lay. In contrast, none of the J‐line were osteoporotic.

4. None of the nutritional treatments affected trabecular bone volumes. Medullary bone volumes were increased significantly by feeding oystershell or fluoride.

5. There was no phenotypic correlation between egg production and trabecular bone volume in the Hisex hens.

6. The experiment provided evidence that osteoporosis in laying hens, as assessed by trabecular bone volumes, is not caused by calcium deficiency and could not be prevented by any of the nutritional treatments studied.     

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.     

High,low, or familiar? Nest site preferences of experienced laying hens

1. The aim of this study was to investigate which nest heights are preferred by laying hens in the absence of familiar nest locations and whether preferred nest heights are more attractive than a familiar location. In two experiments, a total of 108 hens of four different layer breeds, which were at least 50 weeks of age, were studied.

2. In the first experiment, hens were given individual free choice between nests for 1-week at four different heights (0 cm, 39 cm, 78 cm, and 117 cm above ground). Hens of the four breeds differed in their nest height preferences (P = 0.0013). However, hens of three breeds preferred ground level nests (P < 0.007) and the fourth line showed an equal preference for the ground level and level three, the latter level corresponding to the height of the nests in their home compartments.

4. In the second experiment, hens from the four breeds were given a choice between ground level nests and nests at a familiar location, i.e. at the same location as in their home compartment. Hens of all strains preferred the familiar nest location (P = 0.002) and preferences did not differ between strains (P = 0.77).

5. Laying hens seem to prefer nests at ground level in the absence of a familiar nest. However, if possible, experienced 50 week old hens continue to use a familiar nest location instead of a ground nest location. The results are discussed with respect to a potential primary preference that may be modifiable by experience and with respect to possible relevance in commercial housing.     

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.     

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.     

Plumage loss in medium‐bodied hybrid hens: The effect of beak trimming and cage design

1. Plumage loss was assessed by visual scoring in 288, 78‐week‐old hens, housed as groups of four in battery cages, which differed in the design of the cage front and the position of the nipple drinkers.

2. Half the hens had undergone beak trimming at 18 weeks, but in many cases regrowth had occurred.

3. Plumage damage and loss was significantly reduced in beak‐trimmed birds compared with birds with normal beaks. Tier and cage design had no effect.

4. This finding supports the idea that feather pecking is the important factor in causing plumage damage, rather than abrasion.

5. A comparison between 64 birds in which beak regrowth had occurred, and 64 in which it remained truncated, showed that both groups had similar plumage scores.

6. It appears to be the beak‐trimming procedure which is important; subsequent regrowth being irrelevant.     

Effect of soybean meal substitution by different concentrations of sunflower meal on egg quality traits of white and coloured dwarf dam lines

1. The effect of soybean meal substitution by different concentrations of sunflower meal on egg quality traits of white and coloured dwarf dam lines was investigated.

2. A total of 144 dwarf hens (38 weeks of age) from the same hatch were randomly divided into 12 groups of 12 birds (4 dietary treatments × 3 replicates).

3. A 2 × 4 factorial design was used to study the effect of 2 lines (Factor A) and substitution of soybean meal (SBM) with 4 concentrations (0, 10, 15 and 20%) of sunflower meal (SFM) [Factor B] on egg quality traits of dwarf dam line hens.

4. All the diets were designed to be isocaloric (11?3 MJ ME/kg) and isonitrogenous (180 g/kg crude protein) The duration of the experiment was 12 weeks.

5. Analysis of variance indicated a highly significant line effect. There were non-significant effects of substitution of soybean meal with different concentrations of sunflower meal on egg quality traits except for Haugh unit.

6. White plumaged dwarf broiler breeder dam line produced significantly fewer, but larger, eggs than coloured dwarf dam line hens.     

Individual variation in prelaying behaviour and the incidence of floor eggs

1. Floor eggs are a problem in non‐cage systems for laying hens, as they require secondary egg collecting. Failure to lay in a well‐defined nest site may also be a welfare problem for the hens, but only if their nesting motivation has been thwarted.

2. We investigated the relationships between a hen's prelaying behaviour and its tendency to lay on the floor by recording the behaviour of 20 hens housed individually in wire cages with single littered nest boxes.

3. Most floor eggs (80%) were laid by the same 6 hens. These 6 “floor‐layers” performed more nest seeking behaviour, less nest‐building behaviour and less sitting prior to oviposition than the 14 hens that consistently laid in nest boxes.

4. The incidence of floor eggs declined with age. Both nest and floor laying hens performed less nest seeking behaviour with age. Floor layers, however, increased their performance of nesting behaviour, whilst nest layers performed less nesting behaviour with age.

5. Floor laying hens behaved as if they found the nest box less attractive than nest‐laying hens; perhaps because they had lower nesting motivation, or perhaps because their nesting motivation was as high, but they less readily perceived the nest box as an appropriate nest site.     

Effects of nest linings,pecking strips and partitioning on nest use and behaviour in modified battery cages

1. Nine groups of 4 ISA Brown hens were housed in modified battery cages each containing 3 nest sites. Egg laying was performed exclusively in these sites.

2. In experiment 1, each cage contained one unlined nest (type A), one lined with neoprene rubber (type B) and one lined with rubber with an additional peckable strip of artificial grass attached above the nest rear (type C). Positions of the nests were systematically altered over 45 d.

3. Hens spent most time in and made most visits to nest type C. More eggs were laid in nest types B and C than in nest type A.

4. In experiment 2, all nests were of type C, but nests were divided within each cage either by wire mesh, or a solid nest partition, or no partition. Nesting behaviour was monitored over 20 d for each of the 3 conditions.

5. Hens spent most time in, and made most visits to the nests when solid partitions were present. However, disturbance of nesting birds was also significantly increased by solid partitions. There were no significant effects of partition type on the number or positions of eggs laid in the nests.     

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.     

Changes in the plasma concentrations of prolactin,luteinising hormone,progesterone and d‐(β)‐hydroxybutyrate in turkey hens (meleagris gallopavo), during treatment of broodiness under commercial conditions

1. An experiment was done under commercial conditions to investigate the physiological effects of isolating broody turkey hens, for 72 h, in sand and wire floored pens on the third, 10th and 16th weeks of production.

2. Hens identified as broody and removed from the flock had higher plasma prolactin concentrations than the laying hens at each of the three experimental stages.

3. Confinement in sand and wire floored pens, induced a decline in plasma prolactin concentrations. This decline probably impeded immediate development of broody behaviour. Alternately, levels of prolactin higher than those of laying hens were again measured 7 and 14 days after treatment during third week but not after the 10 th and 16th week of production.

4. Confinement did not induce consistent changes in luteinising hormone (LH) and progesterone concentrations from one period to an other.

5. An increase in the plasma concentration of D‐(/?)‐hydroxybutyrate was observed in the hens which had an egg present in the oviduct on day 2, 3 and/or 4 of the treatment. Subsequently, a decrease in ovulation rate was observed in the hens with higher concentrations of D‐(β)‐hydroxybutyrate while under treatment, during the 10th week of production.

6. These data confirm that the effectiveness of the traditional methods for broodiness prevention under commercial conditions is related to the induction of a decrease of prolactin.     

Influence of Plasma Lipid Composition on Activity of Factors V,VII and X in Single Comb White Leghorn and Fatty Liver Haemorrhagic Syndrome-Susceptible Laying Hens

1.?Plasma lipids were investigated to determine whether they influence the biological activities of specific coagulation proteins Factors V, VII and X.

2.?Factor activities decreased when lipids were depleted from the plasma of Single Comb White Leghorn (SCWL) and Fatty Liver Haemorrhagic Syndrome-susceptible (FLHS) laying hens.

3.?Addition of lipids removed from SCWL laying hens and FLHS-susceptible laying hens into lipid-depleted plasma of both bird strains caused an increase and decrease, respectively, in Factors V and X activities.

4.?Omega-3 fatty acids were negatively correlated to Factors V, VII and X activities. When bird strain was considered, it was significant for Factor X in SCWL laying hens. Omega-6 fatty acids were positively correlated with Factors VII and X for FLHS-susceptible laying hens.

5.?The results suggest that the type of fatty acid in plasma phospholipids influences the activities of Factors V, VII and X and by altering lipid composition in the plasma, activities of coagulation factors may be affected.     

Choice of social conditions by laying hens

1. To test the preferences of hens for particular social conditions when laying, they were provided with choices of nest‐sites varying in seclusion. Three experimental conditions were used.

2. In Experiment 1, nest‐site selection by members of a group of light hybrids was studied in a complex pen‐system. Eggs were clumped in distribution ; only one individual laid in the most secluded part of the system.

3. Experiment 2 provided light hybrids with an extensive outdoor area, but similarly clumped laying was observed; there was no indication that hens attempted to find concealment for nesting.

4. In Experiment 3, hens from a group of light hybrids just coming into lay and from a group of mature medium hybrids were tested singly, in an area that included a cage containing some of their flockmates. Most subjects from both groups laid near the other birds rather than in isolation.

5. In semi‐intensive conditions, the majority of hens are apparently gregarious rather than solitary in their nesting behaviour.