Hens In Cages Research Articles

Effects of Furnished Cage Type on Behavior and Welfare of Laying Hens.

This study was conducted to compare the effects of layout of furniture (a perch, nest, and sandbox) in cages on behavior and welfare of hens. Two hundred and sixteen Hyline Brown laying hens were divided into five groups (treatments) with four replicates per group: small furnished cages (SFC), medium furnished cages type I (MFC-I), medium furnished cages type II (MFC-II), and medium furnished cages type III (MFC-III) and conventional cages (CC). The experiment started at 18 week of age and finished at 52 week of age. Hens’ behaviors were filmed during the following periods: 8:00 to 10:00; 13:00 to 14:00; 16:00 to 17:00 on three separate days and two hens from each cage were measured for welfare parameters at 50 wk of age. The results showed that feeding and laying of all hens showed no effect by cage type (p>0.05), and the hens in the furnished cages had significantly lower standing and higher walking than CC hens (p<0.05). The birds in MFC-III had significant higher preening, scratching and feather-pecking behavior than in the other cages (p<0.05). No difference in nesting behavior was found in the hens between the furnished cages (p>0.05). The hens in MFC-I, −II, and −III showed a significant higher socializing behavior than SFC and CC (p<0.05). The lowest perching was for the hens in SFC and the highest perching found for the hens in MFC-III. Overall, the hens in CC showed poorer welfare conditions than the furnished cages, in which the feather condition score, gait score and tonic immobility duration of the hens in CC was significantly higher than SFC, MFC-I, MFC-II, and MFC-III (p<0.05). In conclusion, the furnished cage design affected both behavior and welfare states of hens. Overall, MFC-III cage design was better than SFC, MFC-I, and MFC-II cage designs.

Dustbathing, pecking and scratching behaviours of laying hens in furnished cages are enhanced by the presence of rubber mats and litter distribution

Furnished cages for laying hens exist in a wide variety of sizes and designs and should be equipped to allow hens to express some of their behavioural priorities. European Council Directive 1999/74/EC stipulates that litter must be provided for pecking and scratching but the type of litter and the pad where litter is delivered are not defined. In the same way, neither the maximum nor the optimum number of birds per cage has been defined. Two successive experiments were carried out to analyse pecking, scratching (PS) and dustbathing (DB) behaviours performed in different furnished cages with different designs. Three group sizes of ISA brown laying hens (20, 40 or 60hens, with the same density in all the cages), with or without additional feed distribution as litter substrate, were compared in the first experiment. The second experiment focussed on DB behaviour and compared two pecking and scratching pads (artificial turf or rubber mats), with or without wheat bran distribution as litter substrate, in groups of 60hens per cage. Irrespective of litter presence, group size, and type of pad, DB and PS were mainly performed in the pecking and scratching area, showing the attractiveness of this area. In the first experiment, feed–litter provision in pecking and scratching area increased PS and DB behaviours, while group size did not affect them. In the second experiment, hens performed more DB in the pecking and scratching area when wheat-bran litter was present than when it was absent. Rubber matting was more attractive to hens for DB than artificial turf matting. Durations of DB bouts were not affected by the presence or absence of wheat-bran litter or the choice of pecking and scratching pad. In furnished cages, hens clearly seek out pads and litter to perform PS, and providing litter (feed or wheat bran) or rubber in pecking and scratching area is attractive for hens to DB in it. However, the cage design could be improved to promote more DB activity, for instance by increasing space of pecking and scratching area in the cage.

Air Quality in Alternative Housing Systems May Have an Impact on Laying Hen Welfare. Part I-Dust.

The new legislation for laying hens in the European Union put a ban on conventional cages. Production systems must now provide the hens with access to a nest, a perch, and material for dust bathing. These requirements will improve the behavioral aspects of animal welfare. However, when hens are kept with access to litter, it is a concern that polluted air may become an increased threat to health and therefore also a welfare problem. This article reviews the literature regarding the health and welfare effects birds experience when exposed to barn dust. Dust is composed of inorganic and organic compounds, from the birds themselves as well as from feed, litter, and building materials. Dust may be a vector for microorganisms and toxins. In general, studies indicate that housing systems where laying hens have access to litter as aviaries and floor systems consistently have higher concentrations of suspended dust than caged hens with little (furnished cages) or no access to litter (conventional cages). The higher dust levels in aviaries and floor housing are also caused by increased bird activity in the non-cage systems. There are gaps in both the basic and applied knowledge of how birds react to dust and aerosol contaminants, i.e., what levels they find aversive and/or impair health. Nevertheless, high dust levels may compromise the health and welfare of both birds and their caretakers and the poor air quality often found in new poultry housing systems needs to be addressed. It is necessary to develop prophylactic measures and to refine the production systems in order to achieve the full welfare benefits of the cage ban.

Systematic review of the effect of perch height on keel bone fractures, deformation and injuries, bone strength, foot lesions and perching behavior

This report provides a summary of four systematic reviews on the impact of perch height on laying hen keel bone fractures, deformation and injuries, bone strength, foot lesions and perching behavior. After conducting a scoping review and identifying outcomes of interest, the review protocols were developed. An extensive literature search was conducted in information sources such as CABI, PUBMED and relevant conference proceedings. 1518 abstracts were assessed for relevance and 9 studies reported perch use and 1 reported keel injuries. No studies reported summary effect sizes; therefore it was not possible to conduct a meta-analysis. In lieu of a formal meta-analysis, a descriptive analysis was conducted, which plotted reported perch height against metrics of perch use. This descriptive analysis was not able to account for lack of independence, differences in sample size and other importance sources of heterogeneity such as cage height. The descriptive analysis suggested a positive association with metrics that measured perch use and height, i.e., increased usage was associated with increased height. © European Food Safety Authority, 2015

Atypical lymphocytes and leukocytes in the peripheral circulation of caged hens

Lymphocytes comprise a family of cells descended from bursa and thymus progenitors whose differentiation is not possible by standard hematology. However, if they are small with a nuclear/cytoplasmic ratio near 1, they are “resting” at least in the microscopic sense. Activation, increases their size, and decreases the nuclear:cytoplasmic (N:C) ratio. Reactive cells are infrequent in healthy animal blood. Their presence indicates an immune response in progress, inflammation, stress, or other pathology. Here the purpose is to describe unusual leukocytes and lymphocytes found in the periphery of commercial hens. Samples of Wright stained blood films obtained from commercial hens housed in modern cages are the data source. Photomicroscopy used an Olympus CX41 light microscope equipped with an Infinity-2 1.4 megapixel charge-coupled device (CCD) Universal Serial Bus (USB) 2.0 camera, at 100× (oil) magnification. Collectively these cells illustrate a continuum between mildly “reactive” to grossly “atypical” states. The description begins with normal resting cells, proceeds to mildly atypical, and concludes with grossly abnormal cells. Bone marrow cells, a source of plasmacytes, are included for comparison. Examples of circulating plasmacytes, large plasmacytoid lymphocytes (LPL), foam cells, and cells expressing properties of more than one lineage are included. The importance of these observations lies in their contribution to cytology, hematology, and immunology. Last, because of the wide use of heterophil:lymphocyte ratios (H:L) as a stress measure they bear directly the welfare issues of caged animals. When cells similar to the types described here are in blood, they indicate stress independent of H:L or other standard measures.

Validation of an automated mite counter for Dermanyssus gallinae in experimental laying hen cages.

For integrated pest management (IPM) programs to be maximally effective, monitoring of the growth and decline of the pest populations is essential. Here, we present the validation results of a new automated monitoring device for the poultry red mite (Dermanyssus gallinae), a serious pest in laying hen facilities world-wide. This monitoring device (called an “automated mite counter”) was validated in experimental laying hen cages with live birds and a growing population of D. gallinae. This validation study resulted in 17 data points of ‘number of mites counted’ by the automated mite counter and the ‘number of mites present’ in the experimental laying hen cages. The study demonstrated that the automated mite counter was able to track the D. gallinae population effectively. A wider evaluation showed that this automated mite counter can become a useful tool in IPM of D. gallinae in laying hen facilities.Electronic supplementary materialThe online version of this article (doi:10.1007/s10493-015-9923-2) contains supplementary material, which is available to authorized users.

Influence of dietary taurine and housing density on oviduct function in laying hens.

Experiments were conducted to study the effects of dietary taurine and housing density on oviduct function in laying hens. Green-shell laying hens were randomly assigned to a free range group and two caged groups, one with low-density and the other with high-density housing. Each group was further divided into control (C) and taurine treatment (T) groups. All hens were fed the same basic diet except that the T groups' diet was supplemented with 0.1% taurine. The experiment lasted 15 d. Survival rates, laying rates, daily feed consumption, and daily weight gain were recorded. Histological changes, inflammatory mediator levels, and oxidation and anti-oxidation levels were determined. The results show that dietary taurine supplementation and reduced housing density significantly attenuated pathophysiological changes in the oviduct. Nuclear factor-κB (NF-κB) DNA binding activity increased significantly in the high-density housing group compared with the two other housing groups and was reduced by taurine supplementation. Tumor necrosis factor-α (TNF-α) mRNA expression in the high-density and low-density C and T groups increased significantly. In the free range and low-density groups, dietary taurine significantly reduced the expression of TNF-α mRNA. Supplementation with taurine decreased interferon-γ (IFN-γ) mRNA expression significantly in the low-density groups. Interleukin 4 (IL-4) mRNA expression was significantly higher in caged hens. IL-10 mRNA expression was higher in the high-density C group than in the free range and low-density C groups. Supplementation with taurine decreased IL-10 mRNA expression significantly in the high-density group and increased superoxide dismutase (SOD) activity in the free range hens. We conclude that taurine has important protective effects against oviduct damage. Reducing housing density also results in less oxidative stress, less inflammatory cell infiltration, and lower levels of inflammatory mediators in the oviduct. Therefore, both dietary taurine and reduced housing density can ameliorate oviduct injury, enhance oviduct health, and promote egg production in laying hens.

On-farm comparison of keel fracture prevalence and other welfare indicators in conventional cage and floor-housed laying hens in Ontario, Canada

The objective of this study was to compare the flock-level prevalence of healed keel bone fractures and to benchmark other indicators of well-being in laying hens housed in conventional cages and single-tier floor housing systems at several points during the production period. Commercial farms in Ontario, Canada, that housed hens in cages (n = 9) or floor barns (n = 8) were included. Flocks were beak-trimmed brown hens of various strains. Each flock was visited at 20, 35, 50, and 65 wk of age. At each visit, 50 hens were weighed, palpated for healed keel fractures, and feather scored over 4 areas of the body. Data were collected from the farm records on cumulative mortality. Keel fracture prevalence was higher in floor-housed flocks compared to cage-housed flocks (48.3 ± 0.04% vs. 24.8 ± 0.03%;P < 0.001). The majority of keel fractures occurred by 50 wk. Cumulative mortality tended to be higher in floor-housed flocks compared to cage-housed flocks (2.13 ± 0.42% vs. 1.29 ± 0.19%;P = 0.078). Mean BW was lower (1,827 ± 28.8 g vs. 1,888 ± 26.8 g;P = 0.02) yet more uniform (CV of BW 9.43 ± 0.40% vs. 10.10 ± 0.32%;P < 0.001) in floor-housed flocks compared to cage-housed flocks. Feather condition was not affected by housing system type (P = 0.618), although it declined with age (P < 0.001). Individual hen factors assessed using Pearson partial correlations indicated that hens with fractures were heavier at 65 wk in both housing types (P < 0.05) and that heavier hens housed on the floor had better feather scores (P < 0.001) from 35 wk onward. Floor-housed hens with fractures had lower feather scores at 35 wk (P < 0.05) but not at 50 or 65 wk. Housing hens in single-tier floor systems increased the flock-level prevalence of keel fractures and resulted in a lower, yet more uniform, BW compared to hens in conventional cages under commercial conditions in Ontario. Benchmarking welfare indicators from alternative housing systems for laying hens is important to ensure that progress is made in improving their well-being.

An examination of the utility of heterophil-lymphocyte ratios in assessing stress of caged hens

To measure stress in caged hens, differential counts of their wing vein blood were used to determine heterophil/lymphocyte (H/L) ratios and total white blood cell counts (TWBC). The H/L values of 18-wk samples from conventionally caged hens (CC) were not statistically different from hens raised in aviaries (AV) when calculated by either of 2 methods (H/L 1 and H/L 2). However, there was a high degree of variation among samples within each cage type. The TWBC data and hematology indicated leukocytosis, leukemoid reactions, and a high frequency of atypia. Reactive lymphocytes, large plasmacytoid lymphocytes, cyanophils, coccinocytes, and atypical heterophils were common. Analysis of 77-wk data indicated significant differences among 3 cage types. The H/L 1 of enriched caged (EN) hens was twice (0.91) that of either AV (0.33) or CC (0.44) hens (P < 0.01); the H/L 2 values were also highest for EN (0.46) versus AV (0.29) and CC (0.34; P <0.01). As was the case with 18-wk samples, TWBC distributions and hematological data indicated leukocytosis, leukemoid reactions, and a high frequency of atypia. Among the likely reasons for the hematological observations was the occurrence of polymicrobial bacteremia and fungemia, both of which could account for high TWBC and atypical cells. Collectively, these observations challenge the general application of the H/L ratio method when applied alone as an indicator of stress and welfare of hens caged in modern systems.

Effects of dietary organic chromium and vitamin C supplementation on performance, immune responses, blood metabolites, and stress status of laying hens subjected to high stocking density

The present study was carried out to investigate the effects of dietary supplementation of chromium-methionine (CrMet) and vitamin C (VC) on performance, immune response, and stress status of laying hens subjected to high stocking density. A total of 360 Hy-Line W-36 leghorn hens (at 26 wk old) were used in a 2 × 3 × 2 factorial arrangement that had 2 cage densities (5 and 7 hens per cage), 3 Cr levels (0, 500, and 1,000 ppb as CrMet), and 2 dietary VC levels (0 and 500 ppm as L-ascorbic acid). The trial lasted for 12 wk. The first 2 wk were for adaptation (26 to 28 wk of age), and the remaining 10 wk served as the main recording period. In addition to performance, immune response to Newcastle disease virus (NDV) was assessed at d 7 and 14 postvaccination. Also, the birds’ stress status was evaluated by analyzing appropriate plasma metabolites. The results showed that hens in cages with higher stocking density had lower hen-day egg production, egg mass, and feed intake compared with those in normal density cages (P < 0.05). Dietary CrMet supplementation caused significant increases in egg production and egg mass (P < 0.01). There were significant Cr × VC interactions related to egg production and feed conversion efficiency (P < 0.01); dietary CrMet supplementation was more effective in improving egg production and feed conversion ratio in VC-unsupplemented diets. Although plasma concentrations of triglycerides and high-density lipoproteins were not influenced by dietary treatments, supplemental CrMet decreased plasma cholesterol levels (P < 0.05). Plasma insulin and glucose levels of hens kept at a density of 7 hens/cage were significantly higher than those of hens in normal cage density (P < 0.01), and dietary CrMet supplementation decreased plasma concentrations of insulin (P < 0.001) and glucose (P < 0.01), with higher impacts in high stocking density-challenged hens. While high stocking density caused a marked increase in plasma corticosterone (P < 0.01), both supplemental CrMet and VC decreased it to near normal levels. There were significant stocking density × Cr interactions related to plasma insulin and corticosterone concentrations (P < 0.01); supplemental CrMet was more effective in lowering these hormones in high stocking density–challenged hens. The high stocking density challenge suppressed NDV antibody response (P < 0.001), while dietary supplementation of CrMet improved antibody titers against NDV at d 14 post vaccination particularly in hens kept at a density of 7 hens/cage (P < 0.01). From the present observations, it can be concluded that CrMet can improve laying performance largely because it alleviates harmful responses to stressful conditions.

Effects of in ovo injection of bovine lactoferrin before incubation in layer breeder eggs on tibia measurements and performance of laying hens

There is increasing concern about welfare of laying hens in cages, and one aspect of this topic relates to bone fragility. Therefore, bone anabolic components such as bovine lactoferrin (bLF) may be an effective strategy to maintain the integrity and health of bones. A total of 1080 eggs were divided into four groups with three replicates, each comprising 270 eggs; (1) control group was injected with 100 μl of normal saline per egg; (2, 3 and 4) groups including 22.5 (low), 45 (medium) and 67.5 µg (high) of bLF in 100 µl of normal saline per egg. Eggs were incubated and after hatching, chicks were reared to 28 weeks of age. Tibia measurements were obtained at hatch and at 28 weeks of age. Tibia weight at hatch, was not influenced by in ovo injection of bLF in comparison with the control. Eggs injected with the high concentration of bLF (67.5 µg of bLF per egg) showed significant strengthening in laying-hen tibias at 28 weeks of age, as measured by ultimate force and bending stress, compared with the control. Egg weights from hens treated with this concentration of bLF were also significantly greater than the control. Our data suggest that tibia cortical thickness is a suitable variable for evaluating bone status reflecting bone integrity and strength. The present study also shows that bLF (67.5 µg of bLF per egg) injected into layer breeder eggs before incubation can be used to improve bone strength and egg weight of laying hens at 28 weeks of age, while having no detrimental effect on embryo hatchability.

تأثير شكل الرعاية في الصفات الإنتاجية لدجاج بيض المائدة = The Effect of Housing System on Productive Traits of Hens

90 Hens from commercial hybrid Babcock 300-b housed in two housing system, The first was on deep litter ( 60 hens ) and the second in Battery cages ( 30 hens ). The caged hens were showed superiority ( P < 0.05 ) concerning sexual maturity ( - 7.27 days ), eggs production at period 21-37 weeks ( + 0.11 egg/day ) egg weight ( 1.12 g ) and feed intake ( -21 g/hen/day ), as also rose eggs mass, The difference was not significant regarding egg form. The hens on deep litter laid 16.5 % of eggs in out of nests. And those in Battery cages had 0.8 % clickable eggs.

Horizontal transmission of Salmonella Enteritidis in experimentally infected laying hens housed in conventional or enriched cages

The majority of human illnesses caused by Salmonella Enteritidis are attributed to contaminated eggs, and the prevalence of this pathogen in commercial laying flocks has been identified as a leading epidemiologic risk factor. Flock housing and management systems can affect opportunities for the introduction, transmission, and persistence of foodborne pathogens in poultry. The animal welfare implications of different types of housing for laying hens have been widely discussed in recent years, but the food safety consequences of these production systems remain incompletely understood. The present study assessed the effects of 2 different housing systems (conventional cages and colony cages enriched with perching and nesting areas) on the horizontal transmission of experimentally introduced Salmonella Enteritidis infection within groups of laying hens. In each of 2 trials, 136 hens were distributed among cages of both housing systems and approximately one-third of the hens in each cage were orally inoculated with doses of 108 cfu of Salmonella Enteritidis (phage type 13a in one trial and phage type 4 in the other). At regular intervals through 23 d postinoculation, cloacal swabs were collected from all hens (inoculated and uninoculated) and cultured for Salmonella Enteritidis. Horizontal contact transmission of infection was observed for both Salmonella Enteritidis strains, reaching peak prevalence values of 27.1% of uninoculated hens in conventional cages and 22.7% in enriched cages. However, no significant differences (P > 0.05) in the overall frequencies of horizontal Salmonella Enteritidis transmission were evident between the 2 types of housing. These results suggest that opportunities for Salmonella Enteritidis infection to spread horizontally throughout laying flocks may be similar in conventional and enriched cage-based production systems.

Aflatoxins, hydroxylated metabolites, and aflatoxicol from breast muscle of laying hens

Aflatoxins (AF) are toxic fungal secondary metabolites that are pathological to animals and humans. This study identified and quantified AF (AFB1, AFB2, AFG1, AFG2) and their hydroxylated metabolites (AFM1, AFM2, AFP1) and aflatoxicol (AFL) from laying hen breast muscles. Aflatoxins pass from cereal feed to the laying hen tissues, causing economic losses, and from there to humans. To detect the passage of AF from feed to hen breast muscle tissues, an experiment that included 25 Hy-Line W36 121-wk-old hens was performed for 8 d. Hens in individual cages were distributed into 3 groups: a control group, with feed free of AFB1, and 2 experimental groups, with feed spiked with 2 AFB1 dosages: 30 µg·kg−1 (low) or 500 µg·kg−1 (high). The daily feed consumption per hen was recorded and afterward hens were euthanized and breast muscles were collected, weighed, and dried individually. Aflatoxins were extracted by 2 chemical methods and quantified by HPLC. Both methods were validated by lineality (calibration curves), recovery percentage (>80%), limit of detection, and limit of quantification. The AF (µg·kg−1) averages recovered in control breast muscles were as follows: AFB1 (18); AFG1, AFM2, and AFL (0); AFG2 (1.3); AFM1 (52), and AFP1 (79). Hens fed with feed spiked with 30 µg·kg−1 of AFB1 had AFG1 (16); AFG2 (72); AFM1 (0); AFM2 (18); AFP1 (145); and AFL (5 µg·kg−1). Hens with feed spiked with 500 µg·kg−1 of AFB1 had AFG1 (512); AFG2 (7); AFM1 (4,775); AFM2 (0); AFP1 (661); and AFL (21 µg·kg−1). The best AF extraction method was Qian and Yang's method, modified by adding additional AF from both Supelclean LC18 SPE columns; its limit of detection (0.5 ng·mL−1) was lower compared with that of Koeltzow and Tanner, which was 1 ng·mL−1.

Evidence of competition for nest sites by laying hens in large furnished cages

Furnished cages are designed to accommodate behaviour considered important to laying hens, particularly nesting behaviour. Few researchers have studied the degree of competition for nest sites or the extent to which the amount of nest space affects nesting behaviour in large furnished cages. We explored the effect of floor (low 520cm2/bird, high 750cm2/bird)/nest space allowance (low 70cm2/bird, high 100cm2/bird) and overall cage/nest size (small 20,880/2816cm2; large 41,296/5664cm2) on the nesting behaviour of hens in furnished cages. There were six replicates per size×space allowance combination and four resultant group sizes of 28, 40, 55, and 80. Each cage was equipped with a nest located at one end that was fitted with plastic curtains and plastic mesh floors; a smooth plastic mat intended as a scratch area was located on the opposite cage wall. The location of each egg laid within the cage, oviposition times, pre-laying sitting and agonistic behaviours were recorded at various times during the production year. More eggs were laid in the nest area in small cages (91.7±0.2%) than large (77.2±0.5%; P<0.001), with no significant effect of space allowance (P=0.46). Most of the remaining eggs were laid in the scratch area in all treatments. The average peak oviposition time was from 08:00 to 09:00h (lights on 05:00h), but the distribution of eggs laid over time differed with nest location (P=0.02) and cage/nest size (P=0.02). There were more aggressive pecks (0.087±0.010 vs. 0.045±0.005; P=0.004) and threats (0.032±0.005 vs. 0.014±0.002; P=0.02) per bird per 30-min observation in small than large cages with no effect of space allowance (P=0.236; P=0.15). More pecks and threats occurred between 08:00 and 08:30h than the other three time periods, which coincided with the peak oviposition time. Hens in small cages, with low floor and nest space allowance per bird, showed the highest average frequency of agonistic behaviour per bird compared to the other three treatment groups (P=0.04). Nesting behaviour was mainly affected by cage/nest size but not floor/nest space allowance. Differences in cage design or group size may be factors influencing increased competition for nest space. The birds in the smaller cages appeared to be more willing to aggressively compete to lay their eggs in the curtained nest area while more birds in larger cages chose to lay their eggs in an alternative location. Further behavioural research will be able to determine how best to satisfy nesting motivation of hens housed in large furnished cages.

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.

The influence of dietary taurine and reduced housing density on hepatic functions in laying hens

To investigate the influence of dietary taurine and reduced housing density on hepatic functions in laying hens, green-shell laying hens were randomly assigned to 3 groups: a free-range group, a caged group with low-density, and a caged group with high-density. Each group was further divided into the control (C) and taurine-treatment (T) groups. All the test birds were fed the same basic diet, except that the T groups were supplemented with 0.1% taurine. After 15 d, sera and liver were aseptically collected. The results show that dietary taurine supplementation and reduced housing density significantly attenuated physiopathological changes in the liver. When compared with the free-range group, serum alanine aminotransterase and aspartate aminotransterase in the caged hens were significantly higher and were deceased by taurine (P < 0.05). Serum inducible nitric oxide synthase activity in caged hens was higher than that in free-range hens, and taurine reduced serum inducible nitric oxide synthase activities in the low-density group (P < 0.05). Nuclear factor-κB DNA-binding activity increased significantly in the high-density housing group when compared with the other 2 housing patterns and was decreased by taurine (P < 0.05). Taurine reduced the expression of tumor necrosis factor-α mRNA in all 3 rearing patterns, IL-4 mRNA expression in the high-density group, and IL-10 in the low-density group (P < 0.05). Malondialdehyde levels decreased in serum and liver from T groups and serum total antioxidation capability levels increased significantly (P < 0.05) in the low-density group. Dietary taurine supplementation decreased acetyl-CoA and sterol regulatory element-binding protein-1c mRNA expression in the high-density groups (P < 0.05). Taurine significantly increased lipoprotein lipase mRNA expression in the high-density group and peroxisome proliferator receptor mRNA expression both in the low- and high-density groups (P < 0.05). Taurine supplementation reduced total cholesterol levels in the low- and high-density groups, decreased triglyceride and low-density lipoprotein cholesterol levels in high-density groups, and increased high-density lipoprotein cholesterol levels in all 3 rearing patterns (P < 0.05). Our data demonstrate that dietary taurine and reduced housing density offer significant protection from hepatic damage in laying hens.

Effect of perches on liver health of hens

Fatty liver is a common energy metabolic disorder in caged laying hens. Considering that the egg industry is shifting from conventional cages to alternative housing systems such as enriched cages, the objective of this study was to determine the effects of perches on fat deposition and liver health in laying hens. Three hundred twenty-four 17-wk-old White Leghorn hens were housed in 1 of 4 treatments with 9 hens per cage. Treatment 1 hens never had access to perches during their life cycle. Treatment 2 hens had access to perches during the pullet phase only. Treatment 3 hens had access to perches during the laying phase only. Treatment 4 hens always had access to perches. Liver weight, abdominal fat pad weight, BW, liver fat, and circulating alanine transaminase, aspartate transaminase, and adiponectin were determined. Provision of perches during either the rearing or laying phase did not affect liver health in 71-wk-old hens. However, perch access compared with no perch access during the egg laying phase reduced relative fat pad weight. These results suggest that providing perches as a means of stimulating activity reduced abdominal fat deposition in caged hens during the laying period. However, perch access in caged hens was ineffective in reducing fat deposition in the liver and altering enzyme activities related to improved liver function.

Laying hen performance in different production systems; why do they differ and how to close the gap?Results of discussions with groups of farmers in The Netherlands, Switzerland and France, benchmarking and model calculations.

Free range and organic systems expose the laying hen more to unexpected events and adverse climatic conditions than barn and cage systems. In France, The Netherlands and Switzerland the requirements for a hen suitable to produce in free range and organic systems were discussed with farmers. The farmers preferred for these systems a more ‘robust’ hen, more specifically defined as a heavier hen with good eating capacity. Benchmarking of flocks in a web-based management program in The Netherlands from layer flocks finished in 2008 – 2013 indicated that in earlier years indeed mortality among organic and to a lesser extent free range hens was higher than among barn or cage hens. Feed conversion (kg feed/kg eggs) is higher, but the gap is closing. Improvements in management of the hens during rearing and in the layer phase in free range and organic systems seem to be important. Breeding companies take behaviour and performance in non-cage systems into account in their selection programs. Heavier hens need a diet with a lower protein to energy ratio. From model calculations we concluded that in organic systems a heavier hen might be economically profitable, as total feed costs are lower for the heavier hen then for a hen with a lower body weight requiring a diet with a high protein content. For conventional free range hens this is not the case as then the protein content can be adapted by synthetic amino acids. Field studies and cooperation between farmers and breeding organisations will have to show if a strain of heavier hens will be successful in the rather small organic market.

Effect of floor space on the behavior of laying hens in commercial cages

Summary Background: the size of commercial cages has been raised as the major component in the welfare of laying hens. Objectives: to describe the effect of floor space on the behavior of laying hens housed in commercial cages. Methods: one hundred and thirty-five Hy-Line Brown laying hens (aged 25 ~ 50 weeks) were housed in different sized commercial cages and monitored using video technology during 10 h per day at 2-week intervals. Results: total time spent standing, dozing, and sleeping were significantly higher in small cages than in medium and large cages. Total time spent walking was higher in large cages. Cage-pecking frequency was higher in small cages while stretching frequency was higher in large cages. Moreover, preening frequency was lower in small cages. Conspecific pecking was higher in small cages. Conclusions: cage size is a critical factor affecting the behavior of laying hens. This study can help managers to understand spatial relations in caged hens. Key words: animal welfare, cage size, conspecific pecking, Hy-Line Brown, spatial relations. Resumen Antecedentes: el tamaño de la jaula para gallinas en explotaciones comerciales es el principal problema de bienestar animal en esa especie. Objetivo: describir el efecto del espacio de piso sobre el comportamiento de las gallinas ponedoras alojadas en jaulas comerciales. Métodos: ciento treinta y cinco ponedoras Hy - Line Brown (25 ~ 50 semanas de edad) fueron alojadas en jaulas comerciales de diferentes tamaños y se monitorearon utilizando tecnología de vídeo durante 10 horas diarias en intervalos de 2 semanas. Resultados: la duración total de permanencia en pie, yaciendo y durmiendo fue significativamente mayor en jaulas pequeñas que en las medianas y grandes. El tiempo gastado caminando fue mayor en las jaulas grandes. La frecuencia de picoteo a la jaula fue mayor en las jaulas pequeñas y la frecuencia del estiramiento de alas fue mayor en las grandes. Por otra parte, la frecuencia de acicalamiento fue menor en las jaulas pequeñas. El picoteo entre gallinas fue mayor en las jaulas pequeñas. Conclusiones: se encontró que el tamaño de la jaula es un factor crítico que afecta el comportamiento de las gallinas ponedoras. Este estudio podría ayudar en el manejo de la gallina ponedora enjaulada al mejorar la comprensión sobre las relaciones espaciales en dicha especie. Palabras clave: bienestar animal, Hy-Line Brown, picoteo conespecífico, relaciones espaciales, tamaño de la jaula. Resumo Antecedentes: o tamanho da gaiola para galinhas de granjas comerciais é a principal questão do bem-estar animal nesta espécie. Objetivo: descrever o efeito do espaço sobre o comportamento de galinhas poedeiras alojadas em gaiolas comerciais. Métodos: 135 Hy-Line Brown (25-50 semanas de idade) foram alojadas em gaiolas comerciais de diferentes tamanhos e foram monitoradas utilizando a tecnologia de vídeo durante 10 horas por dia, em intervalos de duas semanas. Resultados: o tempo total gasto em pé, deitado e dormindo foi significativamente maior em gaiolas pequenas do que em gaiolas de porte mediano e grande. O tempo gasto caminhando foi maior em gaiolas grandes. A frequência de bicar a gaiola foi maior nas gaiolas pequenas e a frequência de alongamento das asas foi maior em gaiolas grandes. Além disso, a frequência de limpeza por elas mesmas foi menor em gaiolas pequenas. A bicagem entre as galinhas foi maior em gaiolas pequenas. Conclusões: verificou-se que o tamanho da gaiola é um fator crítico que afeta o comportamento das galinhas poedeiras. Este estudo pode ajudar no manejo de galinhas poedeiras para melhorar a compreensão das relações espaciais nesta espécie. Palavras chave: bem-estar animal, Hy-Line Brown, bicar conspecífico, relações espaciais, tamanho da gaiola.