IntroductionKeel bone damage is a severe animal welfare problem in laying hens. Although it is influenced by husbandry and diet, the selection for laying performance seems to play a key role.Materials and MethodsIn order to learn more about the pathogenesis of keel bone damage, this study aims to characterize and compare keel bone health and potentially related traits in Lohmann Selected Leghorn (LSL, n = 12) and two low-performing genotypes that have not intensively been selected for laying performance: Junglefowl phenotype (JF, n = 14) and Sumatra (Su, n = 12). X-ray imaging, blood sampling, and ultrasonography were conducted at five different time points between the 16th and 72nd week of age. The X-ray images were evaluated for fractures, deviated keel bone area, radiographic density, length, and ossification of the keel bone. Blood samples were used to determine blood ionized calcium, as well as plasma total calcium, phosphate, and 17-β-estradiol. Laying activity and eggshell quality were assessed at group level. Ultrasonography was used to detect visible follicles and assess pectoral muscle thickness.ResultsKeel bone fractures were detected in five out of twelve LSL hens, but in none of the two low-performing genotypes. The first egg was laid distinctly earlier in LSL than in JF and Su (18th vs. 24th and 31st week of age, respectively). Keel bone ossification was completed significantly later in Su than in LSL and JF, but there was no significant difference between the latter two. Visible follicles at the ovary were associated with significantly higher plasma calcium and 17-β-estradiol levels.DiscussionThis study provides a deeper insight into keel bone health and related traits in LSL and low-performing chicken genotypes. Our findings indicate that the earlier onset of lay in LSL does not correspond with earlier keel bone maturation, which could increase later susceptibility for keel bone fractures.

Continuous activity monitoring using motion sensors provides a non-invasive method to assess pig general behavioural activity and detect potential welfare issues on group level in commercial housing systems. In the current study, motion sensors were installed in rearing and fattening pens on four farms (18 pens in total, 18–40 pigs per pen) over multiple trials. Based on daily tail inspections 4977 observation days were classified into control (C, without tail lesion), pre-tail lesion (P, last seven days before tail lesion) and tail lesion (TL) days. Binary classification ablation studies were used to evaluate and understand model robustness, using pairs of classes and varying time windows for P days. Results indicated that a time window of 7 d before the occurrence of tail lesions showed improved classification performance compared to other time windows, allowing the binary distinction of C, P and TL days. Feature selection revealed that not only motion sensor data but also time of year and housing-related variables influenced model performance. The final multiclass model, based on a 7-day time window for P days, achieved a mean testing accuracy >0.7, ranging from 0.75 to 0.85 for the individual classes and lower accuracies for P days compared to TL and C days. However, leave-one-out cross-validation revealed limited generalisation to unseen farms, likely because the general behavioural activity features are not fully independent of farm. Overall, this study demonstrates the potential of motion sensor data for the early detection of tail lesion while indicating that further research is required to improve robustness and generalisability across farm environments.

Tail biting in pigs impairs animal welfare and causes economic losses. Detecting early indicators of tail biting would allow farmers to implement intervention measures and minimize negative consequences. The Bite-o-Mat, a device to automatically detect enrichment manipulation behaviour, was used to assess the suitability of this behaviour as an early indicator of tail biting. The Bite-o-Mat was installed in two rearing and two fattening pens on four farms (16 pens in total, 18–40 undocked pigs per pen). Based on daily inspections of each pig’s tail, days were classified as days with (= TL) or without tail lesions (= control, C). Control days within the 14-day period prior to tail lesions were designated as pre-tail lesion days and included in the TL class. A multi-layer perceptron classifier was used to classify TL and C days based on Bite-o-Mat data. (accuracy = 0.92, sensitivity = 1.00, specificity = 0.71, mean class accuracy = 0.84). Subsequently a time series classifier was trained to predict the class of the following day based on the Bite-o-Mat data of the preceding seven days (accuracy = 0.96, sensitivity = 0.97, specificity = 0.95, mean class accuracy = 0.98). As pre-tail lesion days were included in the TL class, the predicted tail lesion could occur any time from the next day up to 14 day later. Altogether, these results show the potential of the Bite-o-Mat for the early detection of tail lesions due to tail biting in pigs during multiple production periods.

Alternative hatching systems compared to conventional hatchery-hatched systems showed positive effects on welfare of broiler chickens. In order to investigate an additional positive effect of elevated platforms, two hatching methods (on-farm [OH] vs. hatchery-hatched [HH]) and two environments from the first day onwards (with elevated platforms [enriched] vs. without elevated platforms [control]) were combined and investigated using a 2 × 2 factorial design. In three consecutive trials, the combination of the four treatments were repeated eight times each. One thousand six hundred fast-growing broiler chickens (Ross strain) were reared in a mixed-sex system. Chick quality was assessed at hatch and performance parameters and behavior parameters were measured during the entire rearing period of 35 d. For the statistical analysis, LME's and GLMM's were used depending on the data. In general, hatching system and housing environment showed no interaction. There were no differences in hatchability between treatment groups (p=0.93). However, OH chickens showed a higher body weight throughout the rearing period (all p<0.001). OH chickens had a lower body temperature than HH chickens (p=0.002) during the rearing period. OH chickens compared to HH chickens tended to show a higher usage of elevated platform at night (p=0.07). The enriched groups showed higher activity (p<0.0001), but no improved walking ability (p=0.82) than the control groups. The differences in performance and behavior were low between hatching systems and may be related to the short period of feed and water deprivation and the lack of long commercial processing and transportation procedures in the HH treatment group in our experiment. Overall, both on-farm hatching and elevated platforms can lead to an improvement of performance and activity parameters and, thus, an improvement of certain aspects of animal welfare but both factors do not seem to interact with each other.

Tail biting is one of the biggest welfare problems in pigs. However, depending on the individuals involved (e.g., tail biter/victim), pigs seem to change their behaviour prior to tail biting events, which raises the possibility of early detection and thus prediction and prevention of tail biting. In this retrospective explorative study, we used datasets from four different studies with 9 trials of rearing (4 pens/trial with 24 pigs/pen) and fattening (8 pens/trial with 12 pigs/pen) that focused on the exploration behaviour of undocked pigs towards plant-based enrichment materials. From this dataset, we identified 8 pens from rearing (n = 192 pigs) and 6 pens from fattening (n = 72 pigs) in which individual tail biters were identified. From this dataset, we investigated whether any a priori behavioural changes in exploration or feeding could be identified with respect to tail biting. Furthermore, the effects of weight parameters from suckling to fattening were examined. Using linear mixed effects models, we found that exploration duration was linked to days prior to tail biting in rearing, depending on CatPig (category of pigs: biter, victim, neutral pig) (P = 0.001), in fattening independent of CatPig (P<0.0001), and by duration, amount and frequency of feed consumption in fattening (P<0.0001). Some weight parameters covaried with CatPig in rearing (weight-gain suckling: P = 0.0018; weaning weight: P = 0.019) and fattening (weaning weight: P = 0.07; start weight at fattening: P = 0.03; weight-gain rearing: P = 0.02). Suitable indicators for future early detection trials of tail biting could be exploration duration in rearing and fattening and feeding data in fattening. Moreover, weight parameters in rearing and fattening and exploration duration in rearing may be used to identify individual pigs that might become tail biters in an upcoming tail biting event. The retrospective explorative nature of our analysis revealed interesting patterns; however, further studies are needed to confirm our findings.

Bone damages in laying hens are of great concern in poultry farming. Besides various risk factors like housing systems or nutrient supply during egg production, it has often been hypothesized that genetically high-performing laying hens may be more prone to bone damages. The relevance of dietary support during the rearing period of pullets for optimal bone development has been little addressed so far. In the present study, an increasing dietary vitamin D3 content within EU legislation was tested during the first 12 weeks of life in two high and two moderate-performing pullet lines (white and brown layer lines). For this purpose, a total of 940 chickens of both sexes were housed at the Institute of Animal Welfare and Animal Husbandry (Friedrich-Loeffler-Institut, Germany). The three experimental diets differed only regarding the added vitamin D3 amount (300/1000/3000 IU Cholecalciferol/kg diet). After every 4 weeks, randomly chosen animals per genotype and dietary treatment were slaughtered for dissection. Serum 25(OH)-Vitamin D3 concentrations reflected the dietary treatment. Body weight differed regarding genotype. No effect of dietary vitamin D3 content as a single influence factor on bone parameters like breaking strength, bone dimensions or mineral content could be shown, but age, sex and genotype had impacts and influenced traits in an interactive manner. Therefore, during the first 12 weeks of the rearing period of layer pullets, the different dietary vitamin D3 contents did not influence performance or bone parameters in the four genetically diverse purebred layer lines. Adjusted dietary vitamin D3 recommendations for pullets depending on genetically predetermined egg-laying performance do not appear to be necessary if dietary vitamin D3 contents are within EU legislation.

Access to outdoor runs for small groups of fattening pigs, particularly in organic farming systems, are applied in practice and has been the subject of several studies. Access to an outdoor run has been shown to improve the welfare of pigs. However, little is known about the use of outdoor runs in large groups of up to 450 pigs. The aim of this study was to examine the usage of an outdoor run with restricted access in such a large group housing system, which involved using an indoor ventilation system when outdoor run access was restricted. A total of 900 pigs kept in two large groups of 450 pigs each were observed during the fattening period. Access to the outdoor run was provided by computer-controlled gates programmed to open at regular intervals during the day between 7:00 a.m. and 6:00 p.m. Opening phases of the gates to the outdoor run were signalled by a visual-acoustic signal. Restriction to the outdoor run was only on the way out, while access from the outdoor run to the inside area was continuously available. In addition to investigating the usage of the outdoor run, we also examined whether the pigs reacted to the visual-acoustic signals indicating the opening of the gates and whether the opening phases caused crowding in front of the gates. Furthermore, we evaluated the soiling of both the indoor area and the outdoor run. In these large group housing systems, the fattening pigs used the outdoor run continuously during the day, despite the restricted access. On average, 13.6 % of the fattening pigs were present in the outdoor run. No crowding, i.e., exaggerated accumulation of pigs, was observed at the gates during the opening phases. The fattening pigs mainly soiled two areas: an outdoor area near the fence and an uncovered lying area inside the barn. Our results from two large groups of pigs revealed, for the first time, important insights into how such groups use outdoor runs and automated gates.

On-farm self-assessments are legally required since 2014. Livestock farmers have to check the welfare of their animals regularly and systematically by assessing animal welfare indicators ( 11 (8) TierSchG). This allows potential animal welfare problems to be identified at an early stage and improvement measures to be introduced. A standardized assessment of animal welfare indicators is a prerequisite for the comparability of the results of an on-farm self-assessment. The guidelines "Animal welfare indicators: practical guide- cattle/pigs/poultry", enable livestock farmers to systematically assess animal welfare on their farms, were investigated regarding their feasibility and reliability and amended based on the results. An online training course that enables livestock farmers and other interested parties to reliably assess animal welfare indicators, as well as an Excel (R) application that can be used for data collection and automated calculation of results at farm level, are available free of charge on the Internet. In consultation with numerous experts, reference values were elaborated in a multi-stage process by means of a Delphi survey, literature review and expert panels. Livestock farmers can use these to compare their results and assess whether there is a need for action to improve animal welfare on the farm.

Pigs try to separate their lying area from the dunging area. However, due to several factors such as pen design, increasing ambient temperatures, or lack of space, pigs often lie in the dunging area or defaecate in the lying area, resulting in increased pen and animal soiling. Besides poor hygienic conditions, this may also lead to increased ammonia emissions. Thus, proper changes to support the structure of conventional pens may help facilitate better elimination behaviour of pigs and establish and maintain their functional areas, including dunging areas. In this study, we investigated the effect of measures to help pigs use pre-defined functional areas. The study was done on a conventional farm in pens with fully slatted floors. Pen and animal soiling was recorded by a scoring scheme in a total of 37 pens during two fattening periods. In the first fattening period (baseline period), the pen design remained unchanged to evaluate the status quo. In the second fattening period (treatment period), certain changes in 16 test pens were done to structure the pen into a designated dunging and a resting area. The remaining 21 pens served as control pens. Changes included installation of LED spotlights, partly open pen partitions, and re-arrangement of nipple drinkers and hay racks. To compare the soiling of pens, the difference in pen soiling was calculated both between the baseline and the treatment periods and the control and test pens. As a first step, the difference in pen soiling between the control and test pens within both fattening periods was compared. Additionally, to control for changes in pen soiling over time, the differences between the pen soiling of the control pens during the baseline period and the treatment period were compared. The same comparison was done for the test pens. In the treatment period, no significant difference in the pen soiling between the control pens and test pens was found. However, over time, i.e., comparing the soiling of test pens and control pens between the baseline and the treatment periods, pigs soiled the designated dunging areas more in the treatment period. The fattening pigs in both the test and the control pens were very clean during both fattening periods. Our pen modification treatment that combined changes in LED spotlights, drinker locations, roughage locations, and partly open pen partitions did not result in clear effects. However, we can not rule out that these features can help to structure the pens in a positive way.

This scientific opinion focuses on the welfare of laying hens, pullets and layer breeders on farm. The most relevant husbandry systems used in Europe are described. For each system, highly relevant welfare consequences were identified, as well as related animal-based measures (ABMs), and hazards leading to the welfare consequences. Moreover, measures to prevent or correct the hazards and/or mitigate the welfare consequences are recommended. The highly relevant welfare consequences based on severity, duration and frequency of occurrence are bone lesions, group stress, inability to avoid unwanted sexual behaviour, inability to perform comfort behaviour, inability to perform exploratory or foraging behaviour, isolation stress, predation stress, resting problems, restriction of movement, skin disorders and soft tissue lesions and integument damage. The welfare consequences of non-cage compared to cage systems for laying hens are described and minimum enclosure characteristics are described for laying hens, pullets and layer breeders. Beak trimming, which causes negative welfare consequences and is conducted to reduce the prevalence and severity of pecking, is described as well as the risks associated with rearing of non-beak-trimmed flocks. Alternatives to reduce sharpness of the beak without trimming are suggested. Finally, total mortality, plumage damage, wounds, keel bone fractures and carcass condemnations are the most promising ABMs for collection at slaughterhouses to monitor the level of laying hen welfare on farm. Main recommendations include housing all birds in non-cage systems with easily accessible, elevated platforms and provision of dry and friable litter and access to a covered veranda. It is further recommended to implement protocols to define welfare trait information to encourage progress in genetic selection, implement measures to prevent injurious pecking, rear pullets with dark brooders and reduce male aggression in layer breeders.

In pig housing systems, measures to increase the welfare of pigs by environmental enrichment, establishing different functional areas, and improved space allotment are demanded. One interesting way to achieve these improvements can probably be elevated platforms that can be integrated into already existing pens and be part of new pens. First initial studies on elevated platforms for pigs were conducted about 30 years ago, but interest somehow faded out. Due to possible positive effects of elevated platforms on pig welfare, research on this topic has currently re-increased. This review provides an overview on the existing literature, while discussing different designs of platforms and ramps, the biological ability of pigs to use elevated platforms and ramps, advantages and disadvantages for both pigs and farmers, and methods used to evaluate the effects of the platforms on pigs. In summary, due to their biological abilities, pigs are able to use elevated platforms and accept them well. However, ramp design affects the usage and the accessibility of the platform in rearing and fattening pigs. A small number of pigs might refuse to use the ramp to the platform and might only benefit indirectly. Performance, health and behavior of pigs are not negatively affected by elevated platforms. Compared to pigs kept in pens without elevated platforms, aggressive behavior and tail biting can even be reduced in pens with platforms. Increasing space allotment in existing stables by installing elevated platforms has been calculated 50 % less expensive compared to increasing space allotment by new buildings. However, to our knowledge, within the European Union elevated platforms may only be accounted as unobstructed area for pigs in some countries.

Elevated platforms are a suitable possibility to enrich the environment of broiler chicken and, thus, improving their welfare. Early detection of health problems additionally contributes to an improved welfare of chickens and, at the same time, helps the farmer to optimize production efficiency. A prototype combined elevated platforms with weighing beams and an algorithm was developed to estimate number of chickens on the platform as well as their activity. To validate the prototype, during two consecutive trials, 1200 mixed-sex broiler chickens were kept for 35 days in 6 pens in total. In each pen, an elevated platform (height × length × width: 0.5 m × 4 m × 0.6 m), consisting of two rectangular steel frames and four load cells, was offered. Overall weight of broilers on the elevated platform was recorded continuously during the entire fattening period by the automatic weighing system. Algorithms were developed and implemented to estimate (i) daily mean weight of a single animal, (ii) number of animals on the platform, and two activity measures: (iii) movement on platform and (iv) number of platform changes from the weight recordings. To validate estimations, weight was recorded manually on 5 days throughout the trial and usage of elevated platforms was analysed via video records with scan sampling. From days 4 to 34, daily mean weight could be estimated using the proposed algorithm. Compared to manual weighing of a sample group at five days per pen, Spearman correlation coefficient was given by 0.9868 (p < 0.0001), and estimation error (RAE) was 11% on average. The number of chickens on the elevated platform could be approximated with deviations of about +19% and Spearman correlation of 0.97 (p < 0.0001) compared to video observations. An explanation for overestimation of animal number are occasional recalibration problems of the weighing system that resulted in measured weights being larger than actual weights. Furthermore, results of automatic approximation of usage behaviour and animal activity based on continuous recordings of the weighing system throughout days 4 to 34 of fattening are shown. In addition to providing an enrichment tool that could help farmers to control weight development of their livestock automatically and continually, first promising observations of anomalies due to heat and illness show that the proposed system could be used for early detection of animal welfare problems.

Access to an outdoor run improves the housing conditions of fattening pigs by an enlarged space allowance, access to different climatic conditions and environmental stimulation. One central conflicting issue regarding outdoor runs is the emission of harmful gases such as ammonia resulting from faeces and urine. However, by establishing appropriate functional areas in fattening pens, the area soiled by faeces and urine can potentially be reduced. Here, we investigated the usage of an outdoor run and the frequencies and locations of defaecation behaviour of fattening pigs kept in groups of ten in eight pens. Usage of the outdoor run was registered by scan sampling at the group level in three observation periods (pigs at 16, 19, and 22 weeks of age). Furthermore, in each pen, two focal pigs were individually marked and continuously observed for 24 h in each observation period to record defaecation behaviour. At the group level, the fattening pigs used the outdoor run mainly during the daytime between 06:00 h and 20:00 h. A total of 99.4% of defaecation events occurred in the outdoor run, most often in the corner next to the wall of the barn. On average, 11.08 ( +/- SD 3.06) defaecation events per pig per day were recorded, whereby the time of day significantly affected the relative frequencies of defaecation behaviour (GLMER, X12 = 4.11, P < 0.043). Fattening pigs defaecated more often during the daytime than during the nighttime. The number of daily defaecations decreased with age. In pens as used in our study, fattening pigs perform nearly all defaecations in the outdoor run and within a small area. This may enable technical possi-bilities to reduce ammonia emissions in pig pens with outdoor runs, such as regular cleaning of dunging areas by an automatic floor scraper.

Different breeds of domestic and junglefowl differ in foraging strategies indicating that domestication resulted in modified energy saving behavioral strategies. In the present study we investigated foraging strategies and foraging-related behavior in 4 lines of laying hens differing in phylogenetic origin and laying performance to analyze a possible relationship between foraging and the level of egg production. High performing brown and white pure bred lines were compared with their low performing brown and white counterparts. To control possible effects on behavior other than genetic effects, all hens were reared and kept in an identical environment. A total of 72 hens from each line were kept in 6 compartments with 12 hens per compartment, respectively. Observations were done for 3 times during one laying period. Foraging strategy was tested by a contrafreeloading (CFL) paradigm. CFL describes a behavior in which animals prefer food that requires effort to obtain, although at the same time food is freely available. The hens were offered a commercial standard diet in one trough and a mixture of wood shavings and commercial standard diet in another trough. The behavior of hens was video recorded and the activity level of individual hens in the litter area was recorded by an antenna-transponder system. The high performing layers showed less CFL and foraging-related behavior compared with their low performing counterparts in both the white and brown layers. Despite differences in CFL, all hens showed a preference for the commercial standard diet compared to the mixture of wood-shavings. Our results show an association between foraging strategy and level of egg production. This suggests that a high level of egg production is accompanied by behaviors enabling the hens to satisfy their higher energy demand more efficiently. Saving energy by reduced activity probably allows them to reallocate energy into reproduction, that is, laying performance.

Tail biting is still an important problem in pig husbandry. In addition to addressing the underlying causes, the negative consequences of tail biting can be mitigated by detecting it early e.g. using behavioural changes and implementing intervention measures. Due to the labour intensity of behavioural observations, it would be highly advantageous to detect behavioural changes automatically. This study aimed at developing and validating an automatic device ("Bite-o-Mat") to assess the individual manipulative behaviour of group-housed pigs. The Bite-o-Mat consisted of a single point load cell (SPLC) that recorded the force with which pigs manipulated a rope, and an UHF-RFID system to individually identify the manipulating pig. Data were recorded in a rearing (8 pigs) and a fattening pen (5 pigs) and validated using twelve hours of video recordings each, distributed across six days. Pigs were observed 596 (rearing) and 277 (fattening) times to manipulate the rope (=manipulation event) in the videos to which the automatically recorded data were compared. Using a linear mixed model, summarising data per manipulation event, it was possible to show that on average stronger forces are exerted on a rope during manipulation events than during times without manipulations and that these forces can be measured by a SPLC (manipulations vs. no manipulations, model estimates in kg; rearing: -0.01 vs. -0.004 (mean), fattening: -0.05 vs. -0.01 (mean)). Based on these results, an algorithm was developed to automatically detect manipulation events using the data of the SPLC. Validation of the algorithm using a second-by-second comparison to the video analysis, showed that it is suitable to detect manipulation events automatically in the rearing and fattening period (sensitivity: 0.60 (rearing and fattening); specificity: 0.87 (rearing), 0.93 (fattening); precision: 0.55 (rearing), 0.58 (fattening); accuracy: 0.81 (rearing), 0.88 (fattening)). In addition, we aimed to identify the manipulating pig with an UHF-RFID antenna. The performance parameters (sensitivity, specificity, accuracy, precision) of the UHF-RFID antenna confirmed that it is sufficiently suitable to detect the pigs within the reading range. Compared with the video recordings, 69% (rearing) and 82% (fattening) of pigs were correctly identified automatically to be the manipulating pigs by the UHF-RFID algorithm. These results indicate that the Bite-o-Mat is not only a promising device to automatically detect manipulative behaviour in group-housed pigs, but also to identify the manipulating animal.

The serotonin transporter (5-HTT) plays an important role in regulating serotonergic transmission via removal of serotonin (5-HT) from synaptic clefts. Alterations in 5-HTT expression and subsequent 5-HT transmission have been found to be associated with changes in behaviour, such as fearfulness or activity, in humans and other vertebrates. In humans, alterations in 5-HTT expression have been suggested to be able to lead to better learning performance, with more fearful persons being better at learning. Similar effects of the variation in the 5-HTT on fearfulness have been found in chickens, and in this study, we investigated effects on learning. Therefore, we tested 52 adult laying hens, differing in their functional 5-HTT genotype (W/W, W/D and D/D) in an operant learning paradigm in three different phases (initial learning, reversal learning and extinction) and in a tonic immobility test for fearfulness. We found that the 5-HTT polymorphism affects the initial learning performance of laying hens, with homogeneous wild-type (W/W) hens being the slowest learners, and the most fearful birds. W/W hens, showed significantly more choices to solve the initial learning task (LME, p = 0.031) and had the highest latencies in a tonic immobility test (p = 0.039), indicating the highest fearfulness. Our results provide interesting first insights into the role of 5-HTT in chickens and its sensitive interaction with the environment. We further suggest that the 5-HTT gene can be an interesting target gene for future breeding strategies as well as for further experimental studies.

The estrogen estradiol-17ß is known as one of the major gonadal steroid hormones with different functions in reproduction. In this study we analyzed estradiol-17ß concentration in laying hens of four pure bred chicken laying lines at four different time intervals of the laying period (17th–19th week of age, 33rd–35th week of age, 49th–51st week of age, and 72nd week of age). The high performing white egg (WLA) and brown egg (BLA) layer lines as well as the low performing white (R11) and brown (L68) layer lines were kept in both single cages and a floor housing system. We investigated whether there were differences in estradiol -17ß concentrations between lines at different ages that could be related to selection for high egg production or phylogenetic origin of the animals, and whether there was an influence of housing conditions on estradiol-17ß. Estradiol-17ß concentrations differed between high and low performing layer lines at all time intervals studied. High performing hens showed higher estradiol-17ß concentrations compared to low performing hens. In all lines, highest estradiol-17ß concentration was measured at their 49th to their 51st week of age, whereas the peak of laying intensity was observed at their 33rd to their 35th week of age. Additionally, hens with fewer opportunities for activity housed in cages showed higher estradiol-17ß concentrations than hens kept in a floor housing system with more movement possibilities. We could show that laying performance is strongly linked with estradiol -17ß concentration. This concentration changes during laying period and is also influenced by the housing system.

Several alternatives to avoid killing male day-old chicks are available. One of these alternatives is to keep dual-purpose chicken strains. The aim of this study was to compare dual-purpose hens (Lohmann Dual, LD) with conventional laying hens (Lohmann Tradition, LT) in terms of performance, animal welfare parameters such as keel bone state and foot pad derma-titis, and perching behavior. We expected a generally equal or even better performance of the dual-purpose hens except for laying performance. Four hundred female day-old chicks were housed in 6 pens (3 pens per strain) and reared until 54 wk of age. Each pen offered a littered area, elevated slatted manure pit, elevated wooden frame with perches or grids and nest boxes on the manure pit. The wooden frame was alternately equipped with perches or grids. The elevated manure pit as well as the elevated structure was accessible via ramp. Productive performance parameters like mortality, total number of eggs and body weight were assessed periodi-cally. In week 49, 132 hens (66 hens per strain) were randomly selected for radiography of the keel bone and assessment of plumage and foot pad state. Perch-ing behavior was analyzed via scan sampling during rearing and laying period, respectively. Statistical ana-lyzes were done with Linear Mixed Effect Model and General Linear Mixed Model. LD had a higher radio-graphic density than LT hens (P = 0.0016), other keel bone parameters (fracture score, P = 0.36; deforma-tion, P = 0.83) showed no differences. The vast major-ity of fractures occurring in both strains were located in the caudal part of the keel bone. During the laying period, usage of elevated structures was higher with grids compared to perches (P < 0.001) and in LD com-pared to LT (P = 0.01). Some animal welfare prob-lems were less frequent in LD compared to LT hens while other problems did not differ between the 2 strains or were even more frequent in LD hens. Grids may be more suitable as resting area than perches and may possibly help to decrease the prevalence of keel bone damage.

When pigs cannot perform innate species-specific behaviours (e.g. rooting or chewing), behavioural disorders, like tail biting, can occur. However, it seems that various enrichment materials enhance the pigs to perform exploration behaviour and therefore can help to reduce and prevent tail biting. The aim of this study was to identify such highly explored plant-based enrichment material for undocked pigs during rearing and fattening. Furthermore, we evaluated the impact of the offered enrichment materials on tail length and injuries. Therefore, we continuously recorded the individuals? exploration durations in 20 groups by using an ultra-high-frequency radio-frequency identification system, installed at material dispensers. Lucerne pellets (LP), straw pellets (SP), chopped hay (CH) and chopped straw (CS) were offered in a systematically alternating order for two-week sections, respectively. At weaning and at days of material change (i.e. eight times in total), animals were weighed and scored for tail length losses and tail injuries. For analysis, the changes in tail length compared to the previous section were calculated as ?-tail-length losses. Our study revealed that the different offered plant-based enrichment materials affected the duration of exploration behaviour (e.g. rooting, nosing or chewing) during rearing (4 groups, LME, p < 0.0001) and fattening (16 groups, LME, p < 0.0001). In piglets, exploration duration was higher for pelletized materials (LP, SP) than for chopped materials. Fattening pigs explored materials of hay (CH) more often compared to straw-based materials (CS, SP). Daily weight gains of rearing pigs were affected by the type of enrichment material offered in the respective section (LME, p < 0.0001). The highest daily weight gains were achieved when CH was offered. Exploration duration during rearing and fattening was affected by section (LME, both p < 0.0001 for rearing and fattening). Exploration duration during rearing was highest in section 4 and continuously increased from the first section to the last section during fattening. During rearing, the plant-based enrichment materials affected tail injuries (GLMM, p < 0.0001) and ?-tail-length losses tended to be affected (GLMM, p = 0.057). Fewest tail injuries and ?-tail-length losses occurred when SP was offered. During fattening, section affected tail injuries (GLMM, p = 0.01). Most injuries occurred during sections 1 and 2. Our results show that pigs of different ages seem to prefer different plant-based enrichment materials. High exploration durations do not necessarily maintain intact tails if material is changed biweekly. However, exploration durations can be maintained at high levels from rearing through fattening period by regularly alternating the provided plant-based enrichment materials.