Association with Different Housing and Welfare Parameters on Results of a Novel Object Test in Laying Hen Flocks on Farm.

The objective of this on-farm study was to determine if flocks showing feather damage and/or cannibalism would have a higher fear response to the novel object (NOT) and the association between different housing and welfare parameters on results of the NOT. Therefore, 16 flocks were observed during the laying period in Germany. In total, there were six barns, seven free-range, and three organic flocks. The plumage and integument condition of 50 birds of each flock were evaluated at 4 different times during the laying period (V1: 18th to 23rd week of life, V2: 26th to 35th week of life, V3: 49th to 57th week of life, V4: 61st to 73rd week of life). At the same observation times, the NOT was performed in the flocks (at four different locations per visit time). Based on the average number of hens gathered around the novel object (NO) within the period of two minutes, conclusions can be made about the fearfulness of the flock. The present study shows that the more fearful a flock was, the more frequent feather damage (p < 0.001) and cannibalism (p < 0.01) occurred. Age and flock size were associated with fearfulness. Fearfulness of hens increased with the increasing age of hens (p < 0.001) and with an increasing flock size (p < 0.001). Hens of white feather color appeared to be more fearful than brown hens (p < 0.001). Hens kept on barn farms showed significantly lower numbers of hens around the novel object (p < 0.001) than on free-range farms, which possibly indicates that having permanent access to outdoor space generally appears to be associated with the fearfulness of a flock.

Footpad Monitoring: Reliability of an Automated System to Assess Footpad Dermatitis in Turkeys (Meleagris gallopavo) During Slaughter.

Footpad dermatitis (FPD) is an indicator of animal welfare in turkeys, giving evidence of the animals' physical integrity and providing information on husbandry management. Automated systems for assessing FPD at slaughter can present a useful tool for objective data collection. However, using automated systems requires that they reliably assess the incidence. In this study, the feet of turkeys were scored for FPD by both an automated camera system and a human observer, using a five-scale score. The observer reliability between both was calculated (Krippendorff's alpha). The results were not acceptable, with an agreement coefficient of 0.44 in the initial situation. Therefore, pictures of 3,000 feet scored by the automated system were evaluated systematically to detect deficiencies. The reference area (metatarsal footpad) was not detected correctly in 55.0% of the feet, and false detections of the alteration on the footpad (FPD) were found in 32.9% of the feet. In 41.3% of the feet, the foot was not presented straight to the camera. According to these results, the algorithm of the automated system was modified, aiming to improve color detection and the distinction of the metatarsal footpad from the background. Pictures of the feet, now scored by the modified algorithm, were evaluated again. Observer reliability could be improved (Krippendorff's alpha = 0.61). However, detection of the metatarsal footpad (50.9% incorrect detections) and alterations (27.0% incorrect detections) remained a problem. We found that the performance of the camera system was affected by the angle at which the foot was presented to the camera (skew/straight; p < 0.05). Furthermore, the laterality of the foot (left/right) was found to have a significant effect (p < 0.001). We propose that the latter depends on the slaughter process. This study also highlights a high variability in observer reliability of human observers. Depending on the respective target parameter, the reliability coefficient (Krippendorff's alpha) ranged from 0.21 to 0.82. This stresses the importance of finding an objective alternative. Therefore, it was concluded that the automated detection system could be appropriate to reliably assess FPD at the slaughterhouse. However, there is still room to improve the existing method, especially when using FPD as a welfare indicator.

Corticosterone in feathers: Inter- and intraindividual variation in pullets and the importance of the feather type.

Measuring corticosterone concentrations in feathers of poultry may be suitable to determine birds' exposure to stress. It is thinkable, that in laying hens such information could be helpful as an animal welfare indicator to evaluate adverse husbandry conditions and to predict the risk of developing behavioral disorders, such as feather pecking and cannibalism. Yet, there are some fundamental issues which remain unclear. Therefore, the objective of the current pilot study was to examine the inter- and intraindividual variation of pullets at the end of the rearing period, when most of the feathers are fully grown and animals are reaching sexual maturity. Flight feathers from both wings (n = 4), the tail (n = 2 - 3), and body feathers (n = 1 pool of 3 - 5 feathers) were taken from pullets (n = 10), genetics Lohmann Brown, at an age of 19 weeks who were reared in the same flock (N = 728). Corticosterone analysis was performed applying a validated protocol for laying hens. Results indicate not only high intraindividual, but also high interindividual variation. Mean over all samples was 75.2 pg/mg (± 38.58 pg/mg, n = 76), showing higher intraindividual variation (between feather types; SD: 23.75 pg/mg - 49.38 pg/mg; n = 10 pullets) than interindividual variation (within feather types; SD: 11.91 pg/mg - 49.55 pg/mg; n = 6 feather types). The variation between different feather types within one bird was higher than the variation within one feather type between different birds, indicating that birds a) may respond differently when exposed to stressors and b) corticosterone measurements should be done with the same feather type.

The Effects of UV-A Light Provided in Addition to Standard Lighting on Plumage Condition in Laying Hens.

Natural light with ultraviolet spectrum (UV) influences the birds´ perception, the reflectivity of their plumage and affects bird behavior. Therefore, in Germany, laying hens kept in barns should be provided with daylight inlets. Nevertheless, lighting in laying hen houses with a UV proportion is not common practice and little is known about the detailed effects of UV-A lighting during the entire rearing and production period. The present on-farm study examines the impact of light quality on plumage loss, skin injuries and production parameters of laying hens. Therefore, about 92,000 Lohmann Brown hens with untrimmed beaks were kept on a farm in two different groups. Half of them were housed in a barn containing 10 pens illuminated by additional UV-A light (simulate "daylight spectrum"). The other half in the second barn were equally grouped, but exposed to standard lighting for poultry houses. Health, production parameters and plumage condition were monitored during rearing and production. The study results reveal that additional UV-A light is associated with the occurrence of plumage damage and cannibalistic injuries during production. In all groups, the plumage condition of the hens was intact when the hens started laying and declined with age. Therefore, complex interactions alongside UV illumination, environmental enrichment, feed and feeding strategies as well as other management factors that possibly affected both feather damage and skin injuries must also be taken into account.

Foot Pad Health as Part of On-Farm-Monitoring in Turkey Flocks.

Currently, there is no consistent approach to on-farm and post-mortem foot pad (FP) assessment in turkey husbandry in sampling of both feet, sample sizes of birds and scoring schemes during the production period. Therefore, in a field study, 11,400 turkeys, i.e., 22,800 feet, were macroscopically scored at 4-week intervals, 60 birds per flock per date, in accordance with the scale system of Hocking et al. (1). Spearman's rho was calculated between the foot pad dermatitis (FPD) score of both feet of an individual turkey. Sample size for FPD monitoring was calculated for several flock sizes, considering expected FPD prevalence and the error and confidence level (α = 0.01, 0.05, 0.1). To compare macroscopic to histological findings, ten excised FPs were histopathologically investigated by hematoxylin & eosin staining. To align manual macroscopic FPD evaluations with a technical system, 20 photographic images of FPD were measured using the ImageJ program. The scores of both feet of an individual turkey correlated between r = 0.252 and r = 1.000. Thus, both feet of a bird should be monitored, while the worse foot should be evaluated. As an exemplary sample size for on-farm FPD assessment, 77 turkey poults were calculated in a flock of 4,000 birds with an expected FPD prevalence of 40% and α = 0.1. The sample size of monitored birds within a flock should differ and depend on flock size and expected FPD prevalence. Histopathological findings showed normal and non-affected structures of a macroscopic Score 0 and a moderate ulcer of the macroscopic Score 1 and Score 2. The applied assessment scheme should distinguish first alterations and scar tissue as separate scores to differentiate the need for management intervention vs. the success of management measures that were already implemented. FPD affected areas were given lower Scores and assessed to be healthier when evaluated by an image system, compared to a manual assessment. Furthermore, with regard to an increase in camera-based assessments, the boundary of the metatarsal pad needs to be clarified. In conclusion, a new scoring system is required, as the size of the FP cannot be clearly defined and different tissue textures, as well as valid sample sizes are not currently sufficiently considered.

Risk factors for intramammary infections and subclinical mastitis in post-partum dairy heifers.

The prevalence of intramammary infections (IMI) and subclinical mastitis (SCM) in 436 German Holstein heifers was put in relation with clinical findings of the udder and data regarding individual rearing and housing conditions of the animals. The clinical examination took place on the day of the livestock auction (at approximately 41 d in milk, DIM). On that day, 31% of the heifers had IMI in at least one quarter, and 18% of all quarters were infected. Coagulase-negative staphylococci were the most prevalent bacteria isolated, accounting for 68% of the positive samples. Data were analysed by logistic regression. Criteria such as 'juvenile intersucking', 'teats shorter than 35 mm', 'teats with a diameter <18 mm' and 'udder oedema at the day of the auction' were associated with IMI in heifers during the first 41 DIM. Loose-housing systems during pregnancy (as opposed to tie-stalls), juvenile intersucking, clinical mastitis during the first week after calving, teat diameters <18 mm, and employing organic bedding material in the stables before calving were associated with subclinical mastitis.