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.     

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.     

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.     

Cage size and flooring preferences in litter‐reared and cage‐reared hens

1. Pullets (Ross Rangers) reared commercially either in cages or on deep litter were tested for their responses to small (0.38 × 0.43 m) and large (0.76 x 0.86 m) cages with wire floors and to small and large cages with litter floors.

2. When tested at 29 weeks of age, the birds' responses were significantly affected both by cage size (large preferred to small) and by flooring (litter preferred to wire).

3. No difference in cage preference was apparent between cage‐reared and litter‐reared birds either when they were first tested at 17 weeks or when they were re‐tested at 29 weeks. Birds do not have to be reared on litter in order to be attracted by it.     

Evaluation of bone strength,keel bone status,plumage condition and egg quality of two layer lines kept in small group housing systems

1. The aim of the present study was to determine the influence of large (54 or 60) and small (36 or 40) group sizes and tiers of the small group housing system “Eurovent German” on tibia and humerus bone breaking strength, keel bone status, plumage condition and egg quality for two commercial layer lines, Lohmann Selected Leghorn (LSL) and Lohmann Brown (LB), at the same stocking density (890 or 830 cm²/bird).

2. In 4 consecutive trials, 4752 hens were recorded for keel bone status. Evaluation of plumage condition was made for 1440 hens and bone breaking strength was recorded for 1200 hens. A total of 4962 eggs were analysed for internal and external egg quality traits. Analyses involved 30 small group compartments per trial.

3. The layer line had a much more pronounced influence on humerus breaking strength than on tibia breaking strength.

4. Plumage condition, particularly on the neck, was positively correlated with humerus breaking strength in both layer lines.

5. An average of 34% of LB and 23% of LSL hens showed keel bone deformities, with higher proportions of slight deformities.

6. Slight keel bone deformities, rather than moderate to severe, increased significantly during the laying period.

7. Stocking density had no influence on bone breaking strength, keel bone status and egg quality traits.

8. LB layers had a 1.4-fold higher humerus, but only a 1.06-fold higher tibia breaking strength compared to LSL layers.

9. Tibia breaking strength was significantly affected by the interaction of group size and layer line. LSL layers in small groups had lower tibia breaking strengths than those of the large groups.     

Automatic weighing of layer‐replacement pullets housed on litter or in cages

1. Automatic equipment for estimating mean body weight was tested on layer replacement pullets on litter and in a cage.

2. The automatic method gave as good a record as manual weighing for the purpose of controlling food intake.

3. The results suggest that care has to be taken regarding the time period over which the weighing equipment is used.

4. It is important that as many records as possible are obtained during a period of the day when body weight is not varying substantially.     

Water balance of Colostomised and non‐Colostomised hens at different ambient temperatures

1. The quantities of water gained and lost, and hence the total water balance, were determined in normal and colostomised White Leghorn laying hens at ambient temperatures of 5, 20 and 35 °G.

2. In both groups the water intake and water loss at all temperatures were well balanced.

3. Water to food ratios and water content of excreta of normal hens increased with increasing temperature.

4. The wetter excreta at 35 °C are caused by an increased urine production and not by an increased water passage through the alimentary tract.     

Relationships between age,shell quality and individual rate and duration of shell formation in domestic hens

1. The duration and rate of shell formation was measured individually in each of 44 hens. Comparisons were made between hens of different ages, and also between hens which laid eggs of differing shell qualities.

2. Shell formation began 9–5 to 11 h after the oviposition of the previous egg, increased linearly for 13 h and then plateaued at 1–5 h before oviposition.

3. The variation in egg shell quality observed in two experimental groups of hens was 75% attributable to differences in the rate of shell deposition and 25% attributable to difference in the duration of shell deposition.

4. The mean interval between ovipositions increased with age but neither shell weight, nor rate or duration of shell depositon were affected. The increase in egg weight with age accounted for the decrease in shell quality.

5. Intervals between ovipositions were positively correlated with the duration of shell formation, especially its latter stages.

6. Egg production was negatively correlated with the interval between ovipositions but not with the duration or rate of shell deposition. There was a negative correlation between duration and rate of shell deposition, except in the case of the hens producing eggs of poor shell quality.     

Comparison of changes in production and egg composition in relation to in vivo estimates of body weight and composition of brown and white egg layers during the first egg-laying period

1. The aim of this study was to compare the changes in the production and in the body and egg composition of 45 TETRA SL brown egg layers and 45 TETRA BLANCA white egg layers during the first egg-laying period.

2. Changes in the body composition of the hens were followed in vivo by means of computed tomography (CT) four-weekly, between 20 and 72 weeks of age. The measurements covered the whole body of the hens using overlapping 10 mm slice thicknesses on a Siemens Somatom Emotion 6 multislice CT scanner.

3. The yolk, albumen and shell ratio of the eggs, produced on the days of the CT measurements by the hens, were determined and their composition was analysed chemically.

4. The body fat content of the hens increased continuously until 44 weeks of age and plateaued thereafter in both genotypes. However, the body fat content of the white egg layers was always higher than that of the brown egg layers.

5. The yolk ratio and the dry matter and crude fat content of the eggs of white egg layers were higher than the brown egg layers throughout the experiment.

6. Moderate correlations were observed in both genotypes between the body fat content of the hens and egg yolk ratio of their eggs.     

Effects of age and dietary soybean oil level on eggshell quality,bone strength and blood biochemistry in laying hens

1. The objective of the study was to investigate the differences in eggshell quality, bone quality and serum bone biochemistry markers associated with changes in age and dietary soybean oil levels in laying hens.

2. A total of 54, 19-week-old Hy-Line Brown laying hens were housed in 18 battery cages (3 birds/cage) and randomly divided into three diet treatments for 90 d: control-fat (CF, 1.9% soybean oil), moderate-fat (MF, 7% soybean oil) and high-fat (HF, 10% soybean oil).

3. The hens’ body weights (BW), egg production, egg weights, eggshell thickness and femoral diameter were higher at d 90 than at d 60 or d 30. Meanwhile, feed intake, relative bone weights, all bone strength parameters and serum Ca were lower at d 90 or 60 than at d 30.

4. Compared to the CF hens, the feed intake, BW, abdominal fat pad weights and serum alkaline phosphatase activity were elevated in MF or HF hens. The eggshell thickness, relative femoral and tibial weight, femoral stiffness, femoral modulus, tibial mixed force and serum calcium and phosphorus levels were lower in MF or HF hens than CF hens.

5. These findings suggest that bone loss in caged hens starts from an early stage of the laying period, and dietary oil (particularly with diets over 10% soybean oil) has harmful effects on eggshell quality, bone strength and bone mineralisation from an early stage of the laying period.     

A fishy taint in eggs: Interaction between fishmeal diets and strain of bird

1. Field cases of fishy or crabby taint in eggs have been reported, similar to those caused by feeding rapeseed meal (RSM), even though no RSM was fed. The cause was investigated using Babcock B380 and Warren SSL hens.

2. The taint was due to the inclusion of either 25 or 70 g Icelandic capelin fishmeal/kg of the diet.

3. Babcock hens produced significantly more (17%) tainted eggs than Warrens (1.2%).

4. Tainted eggs were significantly reduced to a very low proportion (1.3%) by the third day of feeding a fishmeal‐free diet.

5. The taint was due to the presence of up to 17 mg/trimethylamine kg in affected eggs.     

Nesting and floor laying by domestic hens in a commercial flock

1. The nesting behaviour of broiler breeders was studied in a commercial flock of nearly 4000 birds kept on deep litter by tagging a sample of 200 hens. Use of nest boxes by tagged birds was recorded on 52 d over 34 weeks.

2. Forty hens were never observed in nest boxes and 33 others were recorded only in ground‐level boxes. These 73 birds were recorded significantly less often in nest boxes and more often apparently laying on the floor than others. Fewer of them perched during observations and they started doing so later than birds which used raised nest boxes.

3. These results suggested that there were consistent floor layers, which had difficulty reaching raised nest boxes, as found previously in experimental conditions. Many or all floor layers may, however, have used ground‐level boxes sometimes.

4. Hens were inconsistent in their use of particular nest boxes, and some even nested in two distinct areas.

5. Most individuals were, however, consistent in their reaction to one or more features of the nest boxes, including height, aspect and area. Individual choices for these features varied, so no boxes were used particularly heavily, with the exception of those at ground level.     

Welfare of layers housed in small furnished cages on Danish commercial farms: the condition of keel bone,feet, plumage and skin

1. An on-farm assessment of keel bone, feet, plumage and skin damage was conducted in layers in small furnished cages to evaluate welfare implications.

2. Thirteen farms participated, all housing Lohmann LSL layers in systems allowing 8 or 10 hens per cage.

3. Each flock was visited at three different ages: 32, 62 and 77 weeks. During each visit, 100 hens were examined for keel bone fractures and deviations, plumage damage, body wounds, foot pad lesions, bumble feet, missing toes and toe wounds.

4. A deterioration with age of the condition of the plumage and keel bone was found (P < 0.001). At 77 weeks of age, 16% of the birds had poor plumage, and 43% of the birds had keel bone damage. In contrast, foot pad lesions were most prevalent at 32 weeks of age (13%), whereas the other foot injuries and body wounds remained at a relatively low level throughout the three ages examined.

5. Prevention of damage to the keel bone, plumage and foot pads should therefore be considered when aiming to improve welfare of laying hens housed in small furnished cages.     

Effect of hesperidin dietary supplementation on hen performance,egg quality and yolk oxidative stability

1. The purpose of this study was to evaluate the effects of dietary supplementation with hesperidin (one or 3 g/kg of feed) for 31 d on the performance, egg quality and yolk oxidative stability of brown and white laying hens (26-wk old).

2. Supplementation with hesperidin did not affect egg production, egg weight and egg quality traits.

3. No hesperidin effect on yolk and plasma cholesterol was observed. A strain effect was found with lower total and per g yolk cholesterol of brown hens in comparison to the white ones.

4. Oxidative stability of egg yolk, expressed as ng MDA/g yolk, was significantly improved in the hesperidin groups even from the first week of supplementation. At the same time, a significant improvement in the oxidative stability of egg yolk due to the incorporation of hesperidin in hens’ diet was observed after 30 and 90 d of storage at 20°C and 4°C, respectively.

5. No hesperidin by strain interaction was detected for any of the traits measured.

6. In conclusion, incorporation of hesperidin to laying hens’ feed did not affect productive and egg qualitative traits. On the other hand, dietary hesperidin supplementation significantly improved oxidative stability of both fresh and stored eggs. Antioxidant properties of hesperidin seem to make it a promising natural agent for improving the shelf life of eggs.     

The effects of feeding regime and stocking rate on the performance of medium‐bodied layers in the humid tropics

1. The effects of housing laying hens 1 or 2 per cage (1 452 or 726 cm² /bird), and three feeding regimes (ad libitum, 70% ad libitum and 6 days/ week) were investigated.

2. With 2 birds/cage egg production and food utilisation were adversely affected, but there were no significant effects on egg weight, food consumption, shell thickness, body‐weight change, mortality and abdominal fat.

3. Food restriction significantly increased body‐weight loss and decreased egg production, food consumption, final body weight and abdominal fat, but had no significant effect on egg weight, shell thickness and mortality. The effect on food utilisation was inconsistent.

4. There were significant interactions between feeding regime and stocking rate for egg weight and final body weight.

5. It is suggested that in the humid tropics birds caged singly could be fed at 70% ad libitum while those caged in pairs should be fed ad libitum to avoid multiple stress.     

Plasma concentrations of luteinising hormone during the ovulatory cycle in hens selected for reduced oviposition interval and maintained in continuous light or a 24 h light: Dark cycle

Plasma luteinising hormone (LH) concentrations were measured during the ovulatory cycle in lines of Australorps and White Leghorns selected for reduced oviposition interval and maintained under continuous light and noise.

2. Selection significantly increased plasma LH concentrations in mid‐sequence ovulatory cycles of Australorps but not in the White Leg‐horns.

3. Selection in the Australorps apparently increased the rate of ovarian follicular maturation, resulting in more frequent LH peaks.

4. The effect of selection on plasma LH concentrations is a function of the lighting condition to which the hens are exposed.     

Effect of dietary supplementation of bacteriophage on performance,egg quality and caecal bacterial populations in laying hens

1. Bacteriophages (BP) have gained increasing attention as a treatment of bacterial infection for animals. However, the data pertaining to dietary application of BP for laying hens have been limited.

2. This study aimed to investigate the effect of dietary BP on laying performance, egg quality and caecal bacterial populations in laying hens.

3. The dietary BP used in this experiment was a mixture of individual BP targeting Salmonella gallinarum, Salmonella pullorum, Salmonella typhimurium, Salmonella enteritidis, Salmonella derby and Staphylococcus aureus.

4. A total of 360 Hy-Line Brown laying hens of 32 weeks of age were allotted to one of three dietary treatments with 6 replicates in a completely randomised design. The basal diet was prepared, and 0.4 or 0.8 g/kg BP mixture was supplemented to the basal diet. Diets were fed to hens for 8 weeks.

5. Laying performance and egg quality were not affected by dietary treatments. As inclusion levels of BP mixture in diets were increased, the DNA copy numbers for Salmonella spp. in the caecal contents decreased linearly, whereas the DNA copy numbers for Escherichia coli in the caecal contents increased linearly.

6. Results indicate that dietary supplementation of BP mixture decreases the target Salmonella spp. populations but increases Escherichia coli populations in the gastrointestinal tract of laying hens with little impact on laying performance and egg quality.     

Effect of gradual acclimation to temperatures up to 44 °C on productive performance of the desert Bedouin fowl,the commercial White Leghorn and the two reciprocal crossbreds

1. The effect of daily exposures to increasing ambient temperatures (for 7 months) on egg production was evaluated in the desert Bedouin fowl of Sinai, a commercial White Leghorn and the two reciprocal cross breds.

2. High ambient temperatures did not adversely affect egg weight, laying rate or output per bird (g egg per day per g body weight) of the acclimated hens.

3. Best productivity was attained during periods of exposure to 38 to 40° C in all breeds.

4. Rates of decrease from maximal productivity to productivity at 42 and 44 °G differed with breed. Productivity of Leghorn and Leghorn x Sinai crossbred decreased curvilinearly above 40 °C, while productivity of Sinai and Sinai ( Leghorn crossbred decreased at 42 °C and then stabilised.

5. When changes in egg weight and laying rate were examined on an individual basis (comparison between successive months), the differences between Sinai and the Leghorn were more pronounced.

6. The results support previous findings that the Sinai breed and its crosses are able to withstand extreme environmental temperatures, reflecting genetic adaptation to desert conditions.     

The response of egg weight to the inclusion of different amounts of vegetable oil and linoleic acid in the diet of laying hens

1. Four diets containing different amounts of vegetable oil and linoleic acid were fed to White Leghorn hens throughout a full laying year.

2. Egg weight was poor with the low fat basal diet but increased in relation to the amounts of maize oil (4 and 30 g/kg) included in the diet.

3. With a diet containing 30 g olive oil/kg, egg weight was similar to that obtained with the diet containing the same amount of maize oil.

4. Rearing the birds on diets containing low or moderate amounts of linoleic acid did not affect the response to fatty acid content of the layer's diet.

5. It is concluded that the requirement of the laying hen for linoleic add is not higher than 9 g/kg but that egg weight does respond to higher dietary amounts of readily absorbable fatty acids.     

Traditional and commercial turkeys show similar susceptibility to foot pad dermatitis and behavioural evidence of pain

1. An experiment was conducted to compare the development and clinical significance of foot pad dermatitis (FPD) in 4 lines of turkey poults kept on wet or dry litter for 6 d.

2. Turkeys kept on wet litter were less active and expressed fewer unique sequences of behaviour than poults kept on dry litter, suggesting that high FPD scores are associated with pain during movement.

3. Heavier lines of turkeys had higher mean foot scores that developed earlier, than those in a traditional line, but the effect was relatively small and not statistically significant after 6 d, whereas there were large differences between individuals within line.

4. Body weight gains were greater, and feed intake was lower in the commercial lines kept on dry litter compared with wet litter. There were no differences in water intake between poults kept on wet or dry litter.