D. Huonnic

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.

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.

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.

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.

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

1. 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. 2. 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. 3. 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)). 4. 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. 5. The present study emphasises that considerable worker exposure to endotoxins may occur in laying houses, especially in alternative systems.

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.

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.