Jenny Stracke
@uni-bonn.de
Institute for Animal Sciences, Agricultural Faculty
University of Bonn
RESEARCH, TEACHING, or OTHER INTERESTS
Animal Science and Zoology, Agricultural and Biological Sciences
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
F. May, B. Spindler, J. Müsse, K. Skiba, N. Kemper, and J. Stracke
Elsevier BV
Johanna Müsse, Helen Louton, Birgit Spindler, and Jenny Stracke
MDPI AG
The objective of this study was to analyze sexual dimorphism with regard to the bone quality of Ross 308 broilers. The relationship between carcass traits, performance and bone quality was analyzed. The effect of sex and age at slaughter was examined in four replicates, always on day 31 and day 38. The weight, length, minimum diameter and breaking strength of the tibiotarsi were measured to determine the bone quality. Female tibiotarsi were shorter, lighter and had a lower minimum diameter and breaking strength compared to male ones. The tibiotarsi of older broilers were found to show higher values in the three-point bending test. The effects on broiler performance were determined by measuring the live body weight, carcass and cut weights. The results demonstrate significant effects of the age at slaughter and the sex (p < 0.001) on all measured parameters, with males always reaching higher values compared to females. A strong correlation of performance and bone parameters could be observed between live weight and weight of the tibiotarsi on both days of data collection. Therefore, it could be beneficial to raise female and male broilers separately. However, in order to make specific recommendations for practice, further knowledge is necessary.
Nina Volkmann, Claudius Zelenka, Archana Malavalli Devaraju, Johannes Brünger, Jenny Stracke, Birgit Spindler, Nicole Kemper, and Reinhard Koch
MDPI AG
Injurious pecking against conspecifics is a serious problem in turkey husbandry. Bloody injuries act as a trigger mechanism to induce further pecking, and timely detection and intervention can prevent massive animal welfare impairments and costly losses. Thus, the overarching aim is to develop a camera-based system to monitor the flock and detect injuries using neural networks. In a preliminary study, images of turkeys were annotated by labelling potential injuries. These were used to train a network for injury detection. Here, we applied a keypoint detection model to provide more information on animal position and indicate injury location. Therefore, seven turkey keypoints were defined, and 244 images (showing 7660 birds) were manually annotated. Two state-of-the-art approaches for pose estimation were adjusted, and their results were compared. Subsequently, a better keypoint detection model (HRNet-W48) was combined with the segmentation model for injury detection. For example, individual injuries were classified using “near tail” or “near head” labels. Summarizing, the keypoint detection showed good results and could clearly differentiate between individual animals even in crowded situations.
R. Ali, M. Dorozynski, J. Stracke, and M. Mehltretter
Copernicus GmbH
Abstract. Automatic detection and tracking of individual animals is important to enhance their welfare and to improve our understanding of their behaviour. Due to methodological difficulties, especially in the context of poultry tracking, it is a challenging task to automatically recognise and track individual animals. Those difficulties can be, for example, the similarity of animals of the same species which makes distinguishing between them harder, or sudden changes in their body shape which may happen due to putting on or spreading out the wings in a very short period of time. In this paper, an automatic poultry tracking algorithm is proposed. This algorithm is based on the well-known tracktor approach and tackles multi-object tracking by exploiting the regression head of the Faster R-CNN model to perform temporal realignment of object bounding boxes. Additionally, we use a multi-scale re-identification model to improve the re-association of the detected animals. For evaluating the performance of the proposed method in this study, a novel dataset consisting of seven image sequences that show chicks in an average pen farm in different stages of growth is used.
Jenny Stracke, Robby Andersson, Nina Volkmann, Birgit Spindler, Jan Schulte-Landwehr, Ronald Günther, and Nicole Kemper
Frontiers Media SA
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 &lt; 0.05). Furthermore, the laterality of the foot (left/right) was found to have a significant effect (p &lt; 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.
Franziska May, Jenny Stracke, Sophia Heitmann, Carolin Adler, Alica Krasny, Nicole Kemper, and Birgit Spindler
MDPI AG
Broiler chickens in Europe are usually raised in a barren environment. Elevated perforated platforms address this problem and can positively influence animal health and welfare. To evaluate the effect of an elevated perforated floor on the behavior of broiler chickens, one of two barns was equipped with a perforated flooring system under the food and water supply. The second barn was used as a control. In total, three fattening periods were observed, with 500 broiler chickens (Ross 308 breed) kept in each barn. To compare the behavior of the birds in these groups, cameras were installed in the two barns. The videos were analyzed by counting the number of birds and observing focal animals while recording their behavior. More animals were observed on the perforated floor than in the littered control area (p < 0.001), but focal animals spent less time on the perforated floor compared to the observed littered area in the control barn (p < 0.05). There were no differences in the length of the recorded behaviors between the treatments. These findings suggest that, in general, the elevated perforated floor is attractive for the animals. However, it does not promote one of the recorded behavior patterns. Our results show that an elevated perforated floor could be an option for structuring broiler barns.
Helen Louton, Shana Bergmann, Andre Piller, Michael Erhard, Jenny Stracke, Birgit Spindler, Paul Schmidt, Jan Schulte-Landwehr, and Angela Schwarzer
MDPI AG
The assessment of foot pad dermatitis at slaughter is a suitable method to assess and monitor the welfare of broilers. The goals of this study were to define and validate a camera-based score that could identify macroscopic lesions of the foot pads, to identify errors, and to assess possible external factors that could influence the assessment. In the first phase 200 feet of broilers and in the second phase 500 feet were collected at slaughter, assessed visually, hung back into the evisceration line, and assessed by an automatic system. The camera score cut-off values were defined in the first (=calibration) phase. In the second (=validation) phase, the performance of diagnosis for these cut-off values was evaluated, and possible errors in the assessment of reference surface area and foot pad lesions were analyzed. The results showed that, in particular, Macro Scores 0, 2, and 3 could be identified with sufficiently high sensitivity. For Macro Score 1, the sensitivity of diagnosis was not sufficiently high in the two evaluated software versions. The current automatic assessment systems at slaughter could be adjusted to the cut-off values in order to classify foot pad dermatitis lesions. Furthermore, software updates can enhance the performance measures and lower the probability of errors.
Lars Schmarje, Monty Santarossa, Simon-Martin Schröder, Claudius Zelenka, Rainer Kiko, Jenny Stracke, Nina Volkmann, and Reinhard Koch
Springer Nature Switzerland
S Kimm, SL Rauterberg, J Bill, J Stracke, N Kemper, and M Fels
Cambridge University Press (CUP)
AbstractIn this case study, a housing system for rabbits (Oryctolagus cuniculus) was developed, complying with the new German Welfare Regulation, and evaluated on-farm with regard to the rabbits’ behaviour during four fattening periods. The housing system was characterised by the large group size of fatteners (maximum 65 animals per group, 12 animals per m2) due to the merging of six former single units for does and their litters, post-weaning. A large elevated platform, a box with a roof (small elevated platform), a tube and gnawing materials were made available per unit. The aim being to assess the suitability of the housing system for rabbits with regard to animal welfare, based on behavioural analyses. Therefore, the use of space by the rabbits (n = 247) was investigated by video analysis (instantaneous scan sampling) during daytime. Additionally, the individual behaviour of 20 focal rabbits in different locations was assessed by continuous sampling. Results showed that rabbits preferred to huddle together in the outer units in the first weeks post-weaning. The highest animal densities were found under and in front of the large and on the small platforms. The large platforms were visited increasingly from the 10th fattening day onwards. Elevated platforms supported resting and comfort behaviours. Non-elevated open-top areas enabled upright positions and locomotor behaviours. Aggression and stereotypic behaviours rarely occurred. We conclude that the housing system supported species-specific behaviour and seemed to cater for the needs of rabbits in terms of welfare. Nevertheless, further investigation is needed to ascertain the effects on animal health and performance.
K. Kulke, N. Kemper, and J. Stracke
Elsevier BV
Nina Volkmann, Johannes Brünger, Jenny Stracke, Claudius Zelenka, Reinhard Koch, Nicole Kemper, and Birgit Spindler
MDPI AG
This study aimed to develop a camera-based system using artificial intelligence for automated detection of pecking injuries in turkeys. Videos were recorded and split into individual images for further processing. Using specifically developed software, the injuries visible on these images were marked by humans, and a neural network was trained with these annotations. Due to unacceptable agreement between the annotations of humans and the network, several work steps were initiated to improve the training data. First, a costly work step was used to create high-quality annotations (HQA) for which multiple observers evaluated already annotated injuries. Therefore, each labeled detection had to be validated by three observers before it was saved as “finished”, and for each image, all detections had to be verified three times. Then, a network was trained with these HQA to assist observers in annotating more data. Finally, the benefit of the work step generating HQA was tested, and it was shown that the value of the agreement between the annotations of humans and the network could be doubled. Although the system is not yet capable of ensuring adequate detection of pecking injuries, the study demonstrated the importance of such validation steps in order to obtain good training data.
N. Volkmann, B. Kulig, S. Hoppe, J. Stracke, O. Hensel, and N. Kemper
American Dairy Science Association
Claw lesions are a serious problem on dairy farms, affecting both the health and welfare of the cow. Automated detection of lameness with a practical, on-farm application would support the early detection and treatment of lame cows, potentially reducing the number and severity of claw lesions. Therefore, in this study, a method was proposed for the detection of claw lesions based on the acoustic analysis of a cow's gait. A panel was constructed to measure the impact sound of animals walking over it. The recorded impact sound was edited, and 640 sound files from 64 cows were analyzed. The classification of animal-lameness status was performed using a machine-learning process with a random forest algorithm. The gold standard was a 2-point scale of hoof-trimming results (healthy vs. affected), and 38 properties of the recorded sound files were used as influencing factors. A prediction model for classifying the cow lameness was built using a random forest algorithm. This was validated by comparing the reference output from hoof-trimming with the model output concerning the impact sound. Altering the likelihood settings and changing the cutoff value to predict lame animals improved the prediction model. At a cutoff at 0.4, a decreased false-negative rate was generated, and the false-positive rate only increased slightly. This model obtained a sensitivity of 0.81 and a specificity of 0.97. With this procedure, Cohen's Kappa value of 0.80 showed good agreement between model classification and diagnoses from hoof-trimming. In summary, the prediction model enabled the detection of cows with claw lesions. This study shows that lameness can be detected by machine learning from the impact sound of hoofs in dairy cows.
Jenny Stracke, Nina Volkmann, Franziska May, Stefanie Döhring, Nicole Kemper, and Birgit Spindler
Frontiers Media SA
Animal welfare is one of the most challenging issues in modern farm animal husbandry. Animal welfare indicators can be used to monitor welfare on farms or at slaughterhouses, with footpad dermatitis (FPD) being one of the most important indicators used in turkeys. Up to now, the severity of FPD has been measured by evaluating the size of altered lesions on the metatarsal pad of birds. However, such lesions are not only found on the metatarsal pads, but alterations can also occur on the digital pads of the animals, the latter is not included in the European standard scoring systems for turkeys so far. The aim of the present study was to give a detailed outline of alterations on the digital pads of turkeys and associate their occurrence to a standardly used five-point scoring system, which is based on alterations of the metatarsal pad only. Therefore, pictures of 500 feet of turkeys from 16 flocks at the end of the fattening phase were taken, using an automatic camera system. Based on these pictures, alterations on the digits were scored according to different parameters (lesions, swellings, and number of affected digits). Furthermore, detailed measurements were conducted using an imaging software. Results were compared with a standardly used five-point scoring system (standard FPD scoring system), based on the metatarsal pad as reference. Results provide no equivalence in occurrence and severity of alterations on the metatarsal pads compared to those found on the digits. Pathologic alterations on the digits were already present at standard FPD scoring level 0; no differentiation became obvious between the higher scoring levels 2–4. Strong correlations were found when comparing percentage of alterations of the standard FPD scoring system to those of a system including alterations on the digits and the metatarsal pad, using the total foot as a reference (rp = 0.9, p &lt; 0.001). This was the first study conducting a detailed analysis of alterations on the digits of turkeys. In conclusion, results of this study show that including the evaluation of alterations on digits could refine the present FPD scoring system, especially when using FPD as an animal welfare indicator.
N Volkmann, J Stracke, SL Rauterberg, B Spindler, and N Kemper
Cambridge University Press (CUP)
AbstractIn Europe, conventional housing systems for finishing bulls (Bos taurus) tend to consist of group pens with a high stocking density. Up until now there have been no regulations in place defining bulls’ space requirements, even although insufficient space allowance is considered to impair animal welfare. Our study aimed to measure the surface area that finishing bulls occupy in standing and lying positions. We observed 46 bulls on a German fattening farm. The animals from one pen were assigned to one of three weight classes (W1: < 450 kg; W2:450-649 kg; W3: ≥ 650 kg), and two pens of each weight class were examined. For image recordings, a camera trap was installed above the pens. To analyse the covered surface, the recorded images (n = 242) were edited. Furthermore, the observed lying postures were differentiated in terms of lying position and stretched-out legs. On average, the areas covered by the bulls increased with class of bodyweight. A finishing bull covered up to 1.21 m2 in a standing position and up to 1.57 m2 in a lying position, the most space being needed in an outstretched position. The calculated values provide information only about the surface a finishing bull covered in different positions in the pen. In practice, additional dynamic and social space must be taken into account for recommendations on space requirements, in order to ensure adequate inter-individual distances, social interaction and characteristic behaviours to improve animal welfare.
J Stracke, D Klotz, P Wohlsein, S Döhring, N Volkmann, N Kemper, and B Spindler
Cambridge University Press (CUP)
AbstractFoot-pad dermatitis (FPD) is an important indicator of animal welfare in turkeys (Meleagris gallopavo). The present study aimed to evaluate the reliability and validity of a commonly used five-point visual score (VC), assessing FPD based on lesion size by implementing histopathological analysis. In 100 turkey feet (20 per scale scored by the VC), the size of both the foot-pad and the alteration were measured. Subsequently, a histopathological analysis was performed, examining the occurrence and severity grade of different parameters. The study addressed three main goals: (i) examining the reliability of the scoring system concerning the evaluated size of FPD; (ii) assessing histopathological parameters to analyse patterns, reflecting the categories of the scoring system; and (iii) finding threshold values to avoid the occurrence of ulcerations. The study found good observer reliabilities for the VC, but measuring the relative size of alterations resulted in divergent values according to the original specifications With regard to the histopathological parameters, no clear patterns were found in the respective VC scoring levels. However, ulcerations revealed a significant effect on the size of the alteration, showing a greater grade of severity with increasing lesion size. Regarding the occurrence of ulcerations, optimum threshold values could be identified even in very small lesions. This study helps contribute to a better understanding of the pathophysiology of FPD. It also raises the question as to whether, in light of animal welfare concerns, threshold values of visual systems should be adjusted to avoid ulcerations, considering the outcome of our histopathological assessment.
Sophia Heitmann, Jenny Stracke, Carolin Adler, Marwa F.E. Ahmed, Jochen Schulz, Wolfgang Büscher, Nicole Kemper, and Birgit Spindler
Elsevier BV
H. Louton, A. Piller, S. Bergmann, M. Erhard, J. Stracke, B. Spindler, N. Kemper, P. Schmidt, B. Schade, B. Boehm,et al.
Informa UK Limited
ABSTRACT The assessment of bird-based welfare indicators plays an important role in the evaluation of bird welfare. The aim of the study was to histologically validate a visual scoring system for hock burn in broilers and to detect threshold values of a visual score to define welfare-relevant alterations in terms of mild lesions or ulcers of the hock. We collected 200 hocks of 39- to 42-day-old Ross 308 broilers after the slaughter process. Each hock was scored visually (“macro scores” 0–4) and evaluated histologically (“micro scores” 0–3), with high scores representing more severe lesions. Although we found a tendency for higher micro scores with increasing macro scores, an exact allocation of macro to micro scores was not possible. For example, macro score 1 could represent micro scores 1, 2 and 3, whereas macro scores 3 and 4 always represented micro score 3 (ulcer). The conditional probability of certain micro scores for given macro scores was estimated using a multinomial logistic regression model. Ulcer showed the highest probability at macro score 1, whereas mild lesions were not found to have an estimated highest probability at any macro score. The depth of inflammation of hock burn lesions increased with increasing macro scores up to macro score 3 with an average depth of 1019 µm. Visually more severe and deeper lesions were also histologically rated with higher scores. Thus, considering limitations, the herein validated macroscopic assessment scheme for hock burn allows an estimation of histological alterations in hocks of broilers. RESEARCH HIGHLIGHTS Histological validation of a visual assessment scheme for hock burn in broilers. Tendency for higher micro scores with increasing macro scores. Estimation of histological score via macro score possible with limitations. Histological depth of inflammation increased with an increasing macro score.
A Piller, S Bergmann, A Schwarzer, M Erhard, J Stracke, B Spindler, N Kemper, P Schmidt, J Bachmeier, B Schade,et al.
Cambridge University Press (CUP)
AbstractIn this study, an appropriate visual scoring system for foot-pad dermatitis was validated, considering the histologically measured depth of the inflammation zone and the histopathological grade (no lesion, mild lesion, ulcer). The aim being to evaluate whether the visual, macroscopic scoring of foot-pad dermatitis can represent the histological, microscopic findings. Two hundred Ross 308 broiler chicken feet (birds aged 39-42 fattening days) were collected at a slaughterhouse and scored macroscopically according to a modified version of the Welfare Quality® Assessment Protocol for Poultry. Afterwards, 200 histological slides (one per foot) were prepared, the extent of the inflammation measured and all slides scored by veterinarian pathologists using Michel et al's modified scheme. The statistical relationship between microscopic and macroscopic score and depth of inflammation were estimated via regression models. Increasing macroscopic score was found to be linked with an increase in microscopic score and the depth of inflammation. In particular, feet without lesions and feet with ulcers were identifiable using the macroscopic score. Macroscopic scoring of foot-pad dermatitis can mirror histological findings once certain limitations are taken into account (superficial lesions were not clearly identifiable). Foot-pad dermatitis is considered a useful indicator of animal welfare and our findings suggest that visual, macroscopic scoring could be a practicable assessment tool.
E. Lühken, T. Nicolaisen, J. Stracke, J. Schulz, and N. Kemper
Elsevier BV
Hinz, Stracke, Schättler, Kemper, and Spindler
MDPI AG
Wet litter is the most important cause of footpad dermatitis in poultry, this in turn being a highly relevant animal-related welfare indicator. This field study was subdivided into two experiments. In Experiment 1, the standard diet was supplemented by 0.2% enriched charcoal, being a non-specific absorber and therefore might be promising in reducing faecal moisture. In Experiment 2, the experimental group received a reduced crude protein diet during weeks 6–13, combined with a 0.2% enriched charcoal supplementation. The trials were each conducted with two batches on three farms under on-farm conditions. The animals were observed at 6, 10, 14 and 18 weeks of age to collect data on body weight and different health parameters. The mortality and litter samples were analysed after slaughtering. In Experiment 1, performance and health were not affected despite higher dry matter content of the litter. In Experiment 2, the weight of birds receiving the protein-reduced diet was decreased significantly throughout the experiment. However, the slaughter weight did not differ. The mortality was reduced by 0.5% in the experimental group. Therefore, it was concluded that 0.2% of enriched charcoal is not a valuable feed-additive regarding animal health, while temporary protein reduction might have positive effects.
Melanie Schmidt, Jenny Stracke, Katja Kulke, Nicole Kemper, and Birgit Spindler
MDPI AG
Access to adequate foraging material can reduce the occurrence of feather pecking and cannibalism in laying hens. Technical devices may help farmers provide enrichment material more effectively. However, research in this field is rare. On a commercial free-range farm with 15,000 laying hens (Lohmann Tradition), an enrichment device was evaluated from the 30th to the 58th week of age (LW). It ran at five time points (TP) in the afternoon and offered five grams of dried maize silage per hen per day. The numbers of hens residing in defined scratching areas (ScA) either beneath the device (ScA 1 and 3) or in a similar area without the device (ScA 2) were determined. Significantly more hens were found in ScA 1 and ScA 3 when the device was running. On average, only 6.96 (±7.00) hens stayed in ScA 2, whereas 31.45 (±5.38) and 33.83 (±6.16) hens stayed in ScA 1 and ScA 3, respectively. The hen numbers for ScA 1 and ScA 3 did not differ significantly, nor did the TPs have an influence on number of hens within ScA 1 and ScA 3. The number of hens beneath the device can serve as a potential indicator of the device’s usage.
Nina Volkmann, Jenny Stracke, and Nicole Kemper
Wiley
The aim of the presented study was to validate a three-point locomotion score (LS) classifying lameness in dairy cows. Therefore, locomotion of 144 cows was scored and data on claw lesions were collected during hoof trimming. Based on latter data a cluster analysis was performed to objectively classify cows into three groups (Cluster 1–3). Finally, the congruence between scoring system and clustering was tested using Krippendorff’s α reliability. In total, 63 cows (43.7 per cent) were classified as non-lame (LS1), 38 (26.4 per cent) were rated as LS2 with an uneven gait and 43 (29.9 per cent) cows were ranked as clearly lame (LS3). In comparison, hoof-trimming data revealed 64 cows (44.4 per cent) to show no diagnosis, 37 (25.7 per cent) one diagnosis, 33 animals (22.9 per cent) two diagnoses and 10 (7.0 per cent) more than two. Comparing the respective categorisation received by either the cluster analysis or LS in between groups, a high correspondence (79.4 per cent and 83.7 per cent) could be found for LS1 and cluster 1 as well as for LS3 and cluster 3. Only LS2 had partial agreement (21.1 per cent) to cluster 2. However, Krippendorff’s α was 0.75 (95 per cent CI 0.68 to 0.81), indicating a good degree of reliability. Therefore, the results of this study suggested that the presented LS is suitable for classifying the cows’ state of lameness representing their claw diseases.