Aerial dust concentration in cage-housed, floor-housed, and aviary facilities for laying hens.

Agricultural workers, and pig and poultry farmers in particular, are exposed to airborne contaminants including organic dusts, gases, fungi, bacteria, and endotoxins that can have adverse effects on their respiratory health. To date, data comparing the aerial dust concentrations in the different hen-housing systems used by commercial poultry farmers are scarce. An epidemiological study was conducted in commercial housing facilities for laying hens, half of which were housed in a cage system without litter and the remaining half on an on-floor system with litter. The aims were to measure and compare the ambient dust concentrations in the different housing systems and identify any factors in building design and hen management that could influence the dust burden. An average concentration of respirable ambient dusts (≤4 µm) of 0.37 mg/m(3) (95% CI [0.31-0.42]) was measured in the on-floor system, and this value was higher than average values in the cage system {0.13 mg/m(3) (95% CI [0.11-0.14]) P = 0.01}. The highest dust concentration was observed in aviaries (1.19 mg/m(3) [0.80-1.59]). The type of housing and the presence of litter therefore had a preponderant effect on air quality. Dust concentrations in caged buildings were influenced by cage design and rearing practices, whereas litter management, the age of hens, and temperature control were determining factors for dust levels in on-floor houses. This study underlines the need for information and preventive measures to reduce the exposure of poultry workers to bioaerosols, particularly in alternative systems where high levels of ambient dust were observed.

Prevalence of skin lesions in turkeys at slaughter.

1. The aims of this study were (i) to evaluate the prevalence of welfare-related cutaneous lesions in turkeys at the end of the rearing period and (ii) to study the correlations between lesions. 2. The percentage of lesions in each flock was determined by observation at the slaughterhouse. Sixty flocks were investigated in 13 slaughterhouses between April and July 2006. 3. All flocks showed a high proportion of turkeys with footpad lesions, with 40·7% of turkey flocks having severe footpad dermatitis. A significant number of feet had swelling of the footpad and deviated toes (60·0% and 21·4% respectively). Arthritis was observed in 25·4% of the carcases and an average of 30·1% had breast buttons on the keel. 4. Positive correlations were found between evidence of feather pecking and arthritis, toe deviations and swelling of the footpad. Deviated toes, swelling of the feet and feather pecking were negatively linked to the most severe scratches (P < 0·001). 5. A method is proposed to assess turkey welfare at the slaughterhouse based on several criteria: footpad lesions, arthritis, severe scratches, deviated toes, swelling of the footpad and breast buttons.

Plumage condition, body weight, mortality, and zootechnical performances: the effects of linings and litter provision in furnished cages for laying hens.

This experiment was designed to determine the effect of litter provision and lining in nests and pecking and scratching areas on health and zootechnical performances. Research was carried out in furnished cages, each housing 60 beak-trimmed ISA Brown hens. Four different treatments were compared in a factorial arrangement, including 2 different nest linings (artificial turf versus plastic mesh), either used alone or combined with the use of litter (wheat bran) spread over the rubber mat in the pecking and scratching area (PSA). An additional treatment using artificial turf mat in the PSA and nests (as commonly used in commercial flocks) was used to compare the effect of PSA lining in the other treatments. Zootechnical performances (laying rate, egg weight, and feed intake) were unaffected by PSA lining or by nest lining. The use of artificial turf mats in the PSA resulted in less feather loss than rubber mats, especially on breast and cloaca/vent areas. No consequences were observed on BW or mortality. However, the use of plastic mesh in nests was seen to increase mortality in comparison with artificial turf mats, without affecting plumage condition and BW. Although wheat bran provision did not influence feed intake and laying rate, litter provision did result in slightly higher mean egg weight. Moreover, BW tended to be lower when litter was distributed in cages, and neck and breast plumage condition improved. The distribution of litter was not seen to have any effect on mortality. The provision of litter and the lining of the PSA and nests to improve the welfare of caged laying hens have an effect on mortality, plumage quality, and some zootechnical performances. These results show the importance of choosing the most suitable linings and litter to obtain the best possible compromise between the ethological needs of laying hens, zootechnical performance, and animal health.

Histologically-validated footpad dermatitis scoring system for use in chicken processing plants.

1. Footpad dermatitis (FPD) is a recognised welfare problem in broiler chickens. Broiler feet (n = 54) were examined macroscopically and microscopically to determine a reliable correspondence between macroscopic and histological features, and to devise a scoring system that was relevant to bird welfare and easy to use at processing plants. 2. Three types of footpad lesion were defined based on their severity. Type I were mild lesions, visually characterised by scale enlargement and erythema, and histologically by hyperplasia and hyperkeratosis of the epidermis, superficial dermal congestion and oedema. Type II were moderate, superficial lesions, visually characterised by hypertrophic and hyperkeratotic scales covered with yellowish to brownish exudate, and histologically by a prominent pustular and crust-forming dermatitis. Type III lesions were the most pronounced, visually characterised by a thick dark adherent crust, and histologically by extensive ulceration. 3. On the basis of the severity and extent of these three types of lesions, a 5-point scale was devised, i.e. no or type I lesion (score 1), type II lesion (<50% or >50% of footpad, scores 2 and 3 respectively) and type III lesion (<50% or >50% of footpad, scores 4 and 5 respectively). 4. The scoring system has the advantage of making sense in terms of welfare compared with previous schemes. Furthermore, it is histologically validated and easy to use for the routine assessment of broiler welfare in processing plants.

Cage hygiene, laying location, and egg quality: the effects of linings and litter provision in furnished cages for laying hens.

This study investigates the influence of litter provision and linings used for nests and pecking and scratching areas on cage hygiene, laying location, and egg quality. Research was carried out in furnished cages, each housing 60 beak-trimmed ISA Brown hens. Four different treatments were compared in a factorial arrangement, including 2 different nest linings (artificial turf vs. plastic mesh), either used alone or combined with the use of litter (wheat bran) spread over the rubber mat in the pecking and scratching area (PSA). An additional treatment, using artificial turf mat in the PSA and nests (as commonly used in commercial flocks), was used to compare the effect of PSA lining in the other treatments. We observed laying location, the number of dirty and broken eggs, the microbiological contamination of eggshells according to laying location, and general cage hygiene. The use of nests for laying decreased when they were lined with plastic mesh. Eggs laid outside the nest were of lower quality than those laid inside it, and this was particularly true for eggs laid in the PSA. Although hygiene was low on artificial turf mats, eggs laid on PSA covered with a rubber mat were dirtier and had a higher count of mesophilic bacteria on the eggshell than those laid on PSA covered with an artificial turf mat. Rubber mats in PSA were rapidly destroyed and proved to be unsuitable. The provision of litter had no effect on cage hygiene but substantially increased wear on mats. This study shows nest lining and litter provision methods to be key factors that need to be taken into account to encourage the use of nest boxes for laying, and hence, to ensure good egg quality. Further research into new linings for PSA is needed for the future improvement of egg-laying conditions.

Endotoxin concentration in poultry houses for laying hens kept in cages or in alternative housing systems.

Endotoxins as components of organic dust may have adverse effects on the respiratory health of workers in poultry buildings. The move towards more welfare-friendly housing systems for layers may increase worker exposure to air contaminants due to the use of litter. The endotoxin concentrations in the inhalable fraction of airborne dust (below 100 µm) from cage and alternative system houses (on-floor, free range and aviaries) were compared under both experimental and commercial conditions. The endotoxin concentration was higher in experimental aviaries (median: 565 EU/m³, range: 362-1491 EU/m³) than in cage housing (98 EU/m³ (51-470)). In field conditions, the endotoxin concentration in the air of 13 alternative houses was higher (35 to 3156 EU/m³) than in cage system buildings (n = 8, 78-576 EU/m³). It was correlated to the respirable dust concentration (fraction below 5 µm) and to the temperature inside the hen house but no seasonal variation was observed. The present study emphasises that considerable worker exposure to endotoxins may occur in laying houses, especially in alternative systems.

Furnished cages for laying hens: study of the effects of group size and litter provision on laying location, zootechnical performance and egg quality.

The furnished cage is a new housing system for layers. A current trend in furnished cage design is to increase group size and replace the litter box with a mat provided with litter. An experiment was set up to determine the effects of group size and litter provision on laying performance and egg quality of beak-trimmed ISA Brown hens housed in large furnished cages with more than 12 hens. Six treatments, each of 18 furnished cages (768 cm(2)/hen including nest and litter area) were compared in a 3 × 2 experimental trial: three group sizes (S20 (20 hens per cage), S40 (40) and S60 (60)), with or without feed as litter distributed on the mat of the litter area. The provision of facilities per hen was equal in all treatments. Mortality, laying rate, mean egg weight, feed intake and feed conversion ratio were unaffected by group size over the 53-week laying period, and performance exceeded the ISA production standards. The overall percentage of eggs laid in the nest exceeded 95% except that it was slightly lower in group S20 (92.0% ± 6.4% v. S40: 96.0% ± 3.3% and S60: 96.2% ± 2.7%) leading to a higher proportion of dirty eggs (S20: 1.6% ± 2.2%, S40: 1.4% ± 1.5%, S60: 1.0% ± 1.0%). At 66 to 70 weeks, eggs laid outside the nest had a slightly higher count of mesophilic bacteria on the eggshell (5.0 log CFU/egg ± 0.4) than those laid in the nest (4.8 log CFU/egg ± 0.5) but no difference in contamination was observed between group sizes. Litter provision had no effect on mortality, egg weight or egg quality traits except for a higher proportion of broken eggs in cages with litter (5.3% ± 6.2% v. 4.6% ± 5.7%). Providing hens with feed for litter was associated with a higher laying rate (97.3% ± 3.2% v. 94.8% ± 4.4% at 23 weeks) and an apparent improvement in feed efficiency at the beginning of the laying period (feed conversion ratio based on feed consumption at the trough: 2.18 ± 0.06 with litter v. 2.28 ± 0.09 without litter at 25 weeks). The results of this study showed that a high level of productivity and good egg quality could be obtained in large furnished cages. Further research is needed to assess the impact on hens' welfare and performance of using more economically competitive substrates than feed for litter.

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.

Phylogenetic relationship between Dermanyssus gallinae populations in European countries based on mitochondrial COI gene sequences.

Phylogenetic analysis of Dermanyssus gallinae mites originating from UK, France and Italy was performed using partial amplification of the mitochondrial COI gene. Results showed that UK samples reveal the greatest variation and diversity and are linked to one of the French populations highlighting North-South genetic transitions in European red mite populations. Intra-farm variations between mite samples highlighted the diversity between national populations and possibly its origin from the different chemical strategies used in each country.

Risk factors for foot-pad dermatitis in chicken and turkey broilers in France.

A prospective cohort study was conducted in the Brittany region to identify the risk factors related to foot-pad dermatitis (considered an indicator of animal well-being) in chicken and turkey broilers reared under commercial conditions. Factors related to the shed, equipment, litter management and stocking density were recorded; the dependent variable was the prevalence of lesions observed on the slaughterhouse chain. Lesions were scored from 0 (no lesion) to 3 (severe lesion). Our survey lasted from May 1999 to October 2000. Fifty flocks of chicken broilers (15 farms), 27 flocks of female turkey broilers (21 farms) and 41 flocks of male turkey broilers (27 farms) were surveyed. In chicken broilers, 10% of flocks were of high quality (80% of birds with score 0) and this was related to the use of concrete floors with a thin layer of wood shavings. In turkey broilers, 48% of female and 46% of male flocks were of bad quality (>10% of birds with score 3). A poor fan ventilation system (<150m(3)/h/kg) was a significant risk factor. Turkey flocks of high quality were not observed. Stocking density had no influence on the prevalence of foot-pad dermatitis. We concluded that it is possible under high commercial stocking densities to have flocks with a low prevalence of foot-pad dermatitis in chicken broilers, whereas it is not in turkey broilers. Hence in chicken broilers, implementing a monitoring system based on the observation of foot-pad dermatitis prevalence at slaughter appears to be more appropriate than to legislate stocking density. In turkey broilers, it would probably be necessary either to reduce the stocking density drastically or to investigate new systems of floor drainage.

Influence of stocking density, artificial dusk and group size on the perching behaviour of broilers.

1. Perching behaviour of Ross broiler chickens was studied in order to increase the available space at the floor level. Pens (36 m2) were equipped with wooden perches mounted 20 and 33 cm above the litter (5 cm perch length per bird). 2. The influences of stocking density (22 vs 11 birds/m2, experiment 1) and of a 10 min artificial dusk (17 birds/m2, experiment 2) were tested in a 2x2 factorial design (n=4 by treatment) including control pens without perches. In experiment 3, perching behaviour between 2 different group sizes (1020 vs 4590 birds, 17 birds/m2, no replicates) was compared. 3. The percentage of perching birds (PPB) was assessed by scan sampling observations during the 20 to 22 h light period (8 observations per d, 5 d a week, from week 3). In experiment 2, infra-red video recording was performed at the time lights were dimmed and during the dark period. In experiment 1, carcase lesions were noted. In experiment 2, tibia breaking strength of frequently perching birds was compared with controls. Birds were weighed before slaughter and food conversion was calculated. 4. PPB increased with age and density (P<0.01) and was highest at the 22 birds/m2 density during week 6 (mean=10.6%, maximum=13.5%). PPB was not influenced by a 10-min artificial dusk. In experiment 3, PPB was slightly lower during weeks 5 and 6 in the large group size compared to the small group size (6.8% vs 7.9% respectively in week 6). 5. Prevalence of carcase lesions and tibia breaking strengths were unrelated to perch usage. Final body-weights were not influenced by the presence of perches except at the 22 birds/m2 density where males were slightly heavier in the control pens compared with males in pens equipped with perches (2096 g vs 2051 g, P=0.015). Food conversion was independent of the presence of perches.

Influence of stocking density on behavioural, health and productivity traits of turkeys in large flocks.

1. The effect of stocking density on welfare traits of turkeys was studied in 2 experiments. In each experiment 2,633 sexed BUT turkey poults were assigned to 3 rooms, 135 m2 with 1 treatment per room. Because of the large flock size (675,878 and 1080 birds in T1, T2 and T3 respectively) treatments were not replicated 2. Floor space allowances varied according to treatment; for the males: 24 dm2, 18.5 dm2 and 15 dm2 until week 12 and 40 dm2, 31 dm2 and 25 dm2 from week 12; for the females: 16 dm2, 12.3 dm2 and 10 dm2. 2. The scan sampling method in experiment 1 and the focal sampling method in experiment 2 were used to record behaviour at week 6, 9, 12 (males and females), and 16 (males). Birds' ethogram was divided into 7 mutually exclusive behaviours: standing/walking, resting, feeding, drinking, pecking at the environment, pecking at another bird, and preening. Position changes in the pen and the frequency of disturbances of resting birds by other birds were recorded in experiment 2. 3. Gait was assessed at week 12 (females) and week 16 (males). Prevalence of lesions, breast (males), hip and foot (males and females), were recorded at slaughter. Birds were weighed at week 12 (males and females) and week 16 (males). 4. Stocking density had little influence on behaviour except on the frequency of disturbances of resting birds by other birds, which tended to be more frequent at the highest density. 5. Gait deteriorated as stocking density increased. Hip and foot lesions were more frequent at the highest density. Bodyweight decreased significantly with decreasing floor space. 6. The results suggest that turkey welfare was poorer at the highest density than at the 2 lower stocking densities.

Influence of stocking density on some behavioural, physiological and productivity traits of broilers.

In order to investigate the influence of stocking density on broiler welfare, 17,616 Ross chickens were assigned to three different treatments: T1, T2 and T3 with a final stocking density of 27, 35 and 43 kg/m2, respectively (corresponding to an initial density of 12, 16 and 20 birds/m2). Animal welfare was assessed by measuring behavioural, physiological and productivity traits. Behavioural observations included the disturbance frequency of resting birds by other birds, the duration of the lying bouts and the standing/lying ratio. The heterophil/lymphocyte ratios were assessed from blood collected before departure to the slaughterhouse. Main productivity traits were the final live weight and carcass degradation due to foot and pad dermatitis and breast blisters. Most of the observed parameters were adversely affected by the highest density (P < 0.05). Between T1 and T2, some traits tended to demonstrate that a better degree of bird welfare existed in T1 (higher standing/lying postures ratio and final live weight, lower frequency of pododermatitis and hock lesions; P < 0.05) whereas other traits showed no differences (frequency of disturbances by other birds during resting, heterophil/lymphocyte ratio). In conclusion, a stocking density of 43 kg/m2 seemed to induce poor bird welfare whereas it was not clearly demonstrated that 27 kg/m2 was better than 35 kg/m2.

Animal welfare and the intensive production of bovine meat.

After a brief review of the legal framework of animal protection applicable to cattle--including Council of Europe and European Union legislation, as well as French law--the main features of husbandry systems used in the intensive husbandry of veal calves and young cattle are analysed. For veal calves, the standards proposed at the European level do not take into account major differences in the age, weight and quality of veal produced by different Member States. In the case of red meat, the production of baby beef in intensive units leads to some behavioural anomalies, which could be remedied within economic restrictions compatible with the interests of producers and consumers.