Erhöhte Ammoniak- und Aerosolkonzentrationen in Schweineställen können zu gesundheitlichen Schäden bei Tieren und Menschen führen, leistungsmindernd wirken und als Emissionen die Umwelt belasten. Das Hauptziel der Untersuchung bestand darin, eine Methode für die Stallumluftwäsche zu entwickeln und zu evaluieren. Dabei sollte ein Teilstrom der Stallluft entnommen, durch einen mehrstufigen Reinigungsprozess geführt und anschließend wieder in den Stall zurückgeleitet werden, um so die Qualität der Stallluft effektiv zu verbessern. Ammoniak wird dabei aus dem Rohgas in einem flüssigen Medium absorbiert und anschließend über eine Nitrifikations- und Denitrifikationseinheit in atmosphärischen Stickstoff umgewandelt. In einem Technikumsversuch, der sich auf die Reduzierung von Ammoniak bei einer auf 16 Tierplätzen ausgelegten Anlage konzentrierte, zeigte sich, dass sowohl die Nitrifikations- als auch die Denitrifikationsleistung in Relation zur Anlagengröße gering waren. Die Nitrifikationsrate lag bei 0,21 g NOx-N l-1 d-1 (SD = 0,06 g NOx-N l-1 d-1) während die Denitrifikationsrate bei 1,11 g NOx-N l-1 d-1 (SD = 0,37 g NOx-N l-1 d-1) bezogen auf die Anlagenauslegung lag. Die Emissionen von Sekundärgas waren mit 1,3 % der N-Dosierung gering. Bei einer vergleichenden Kostenkalkulation mit der klassischen chemischen Abluftreinigung (Chemowäsche) zeigten sich deutlich höhere Betriebskosten für das getestete Verfahren, was darauf hinweist, dass es momentan noch nicht für den praktischen Einsatz geeignet ist. Es konnten keine Messungen zur Beurteilung der Verbesserung der Stallluftqualität durchgeführt werden.

Cow-calf contact systems are attracting increasing interest among farmers and some are already being implemented into dairy farms. However, a comprehensive assessment of animal welfare in these systems is lacking. One reason for this is the large amount of time required for behavioral observations. However, the increased use of sensors in herd management assistance systems offers new opportunities for automated monitoring of animal welfare. For example, accelerometers can be used to collect activity data for a specific pattern analysis. In this study, ultradian and circadian rhythms of cows were analyzed. The degree of functional coupling (DFC; range of values: 0-1) expresses the extent to which the activity is cyclic to 24 h, and therefore harmonically synchronized with the periodicity of the environment. A DFC of 1 indicates complete adaptation of the cows' activity rhythm to the 24-h day. Additionally, the diurnality index (DI) is used to examine the distribution of diurnal and nocturnal activity. A DI of 1 indicates complete diurnal activity, whereas -1 indicates complete nocturnal activity. The rhythms of healthy and well-adapted animals show high adaptation to the 24-h day, whereas external or endogenous effects can interfere with these rhythms. Although contact with their calves allows cows to behave more naturally, it is possible that calves demanding their mothers' attention may affect the cows' rhythmicity, similar to other external factors. To test this hypothesis, 2 herds of German Holstein cows housed in a mirrored loose housing system were included in the study, which was conducted over 2 experimental periods. Three treatments were applied, differing in contact between cow and calf. The contact dams had either whole-day or daytime contact with their calves, and the no-contact cows were separated from their calves directly postpartum. Accelerometers were used to record and analyze the cows' activity between 59 and 83 DIM, thus excluding the calving and weaning phases. Generalized linear mixed models were used to estimate the effect of treatment (no, daytime, and whole-day contact) on DFC and DI, considering the effects of estrus, deviation of milking start in the evening, and parity (primi- vs. multiparous). Finally, the harmonic period lengths of the activity patterns were extracted to analyze the distribution of the primarily expressed period lengths of the different treatments. In general, the average activity patterns of the cows did not differ between the treatments. However, dams with whole-day contact showed a lower activity peak before milking but a higher activity after evening milking. Nevertheless, the DFC and DI were similar in each group. During estrus, the chance of a maximum DFC decreased and the DI increased. Whole-day contact dams showed the most significant harmonic periods (33 per cow). Nevertheless, the primarily expressed period length (3.4 h) was equal in each treatment. In conclusion, neither contact with the calf nor its daily duration affected the ultradian and circadian rhythms of dams compared with cows separated from their calf.

Monitoring the activity of animals can help with assessing their health status. We monitored the walking activity of fattening pigs using a UHF-RFID system. Four hundred fattening pigs with UHF-RFID ear tags were recorded by RFID antennas at the troughs, playing devices and drinkers during the fattening period. A minimum walking distance, or virtual walking distance, was determined for each pig per day by calculating the distances between two consecutive reading areas. This automatically calculated value was used as an activity measure and not only showed differences between the pigs but also between different fattening stages. The longer the fattening periods lasted, the less walking activity was detected. The virtual walking distance ranged between 281 m on average in the first fattening stage and about 141 m in the last fattening stage in a restricted environment. The findings are similar to other studies considering walking distances of fattening pigs, but are far less labor-intensive and time-consuming than direct observations.

The objectives of the DiWenkLa project (Digital value chains for sustainable small-scale agriculture) are the analysis, development and knowledge, and practice transfer of the use of digital technologies in small-scale regions. In this paper, the application potentials for decision support and farm management are investigated for animal husbandry based on two typical regional examples (automation in horse husbandry and individual animal sensor technology in pasture-based dairy cattle husbandry). It is being demonstrated for horse husbandry that automated feeding of roughage and concentrate feed can reduce signs of stress in horses and significantly reduce feeding labor time. In pasture-based dairy cattle management, sensor technologies enable animal-specific representation of activity data (eating, ruminating, walking) in a temporal-spatial context. The individual animal-related data are an important key area in a holistic approach of feeding, grazing and herd management.

Knowledge about feed intake and adequate nutritional status of dairy cows is important to achieve high milk yield in grazing systems. A possible, but subjective, method to estimate changes in grazing intake could be rumen fill scoring. Thus, a novel flow chart, based on existing criteria for rumen fill scoring was developed to simplify this approach. The first objective of this study was to develop a flowchart to reduce training time for untrained observers and to support the observers in their decision-making process. Therefore, the quality of scoring of four trained observers that used the criteria, originally published by Zaaijer and Noordhuizen (2003), was assessed first. After that, the interobserver reliability of trained observers (control group) and untrained observers that used the novel flowchart was determined. The novel flowchart was tested twice. The second version of the flowchart included the feedback of the first round. To assess if rumen fill scoring is a suitable method for detecting changes in grazing intake was the second objective of this study. Therefore, it was investigated if rumen fill scores could be used to detect decreasing feed intake during a 6-d grazing period with limited feed allocation. The experiments demonstrated that overall agreement between trained observers who used the criteria originally published was moderate (kappa(F) = 0.53). The overall agreement of untrained observers who used the novel flowchart increased from fair (kappa(F) = 0.40) to substantial (kappa(F) = 0.66) between the two versions of the flowchart. Finally, it was found that rumen fill scores decreased, according to decreasing feed allocation for this small sample. In conclusion, the novel flowchart simplified rumen fill scoring, thus facilitating the assessment of rumen fill as a potential method for estimating changes in pasture intake in research and practice. (C) 2022 The Authors. Published by Elsevier Inc. on behalf of The Society for Range Management.

Continuous monitoring of pig posture is important for better understanding animal behavior. Previous studies focused on day recordings and did not investigate how deep learning models could be applied during longer periods including night recordings under near-infrared light from several pens. Therefore, the objective of this research was to study how a suitable deep learning model for continuous 24/7 pig posture detection could be achieved. We selected a deep learning model from over 150 different model configurations covering experiments concerning 3 detection heads, 4 base networks, 5 transfer datasets and 12 data augmentations. For this purpose, we test and validate our models using 4690 annotations of randomly drawn images from 24/7 video recordings covering 2 fattening periods from 10 pens. Our results indicate that pig position and posture was detected on the test set with 84% mAP@0.50 (49% mAP@[0.50:0.05:0.95]) for day recordings and for night recordings 58% mAP@0.50 (29% mAP@[0.50:0.05:0.95]) was achieved. The main reason for lower mAP during night recordings was degraded near-infrared image quality. Our work reports important findings concerning the applicability of deep learning models on night near-infrared recordings for posture detection. The dataset is publicly available for further research and industrial applications.

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.

The rearing of piglets is a demanding phase of pig production partly because of the changing temperature requirements of the piglets during rearing. Piglets need high temperatures in the resting area, especially at the beginning, while the optimal temperature is lower toward the end of rearing. To meet the changing temperature demands of the piglets and also to optimize the pen structure, one floor cooling and two heating systems were examined in this study. In two rearing compartments, four pens with 48 piglets each were equipped with a heated cover above a heated/cooled lying area. The lying behavior and performance of 1152 piglets, in addition to the pen fouling, were recorded over six rearing periods. There was no difference between the two heating systems in the lying behavior. However, the acceptance of the lying area was very high in all pens and periods with heating. The cooling had a significant influence on the lying behavior depending on the rearing week. Significantly more piglets lay on the cooled lying area compared with the control pen during the last weeks. The fouling of the pens was not affected by the cooling or heating systems; however, the fouling in all pens was very low. The tested pen structure in combination with a heating and cooling system is a well-functioning way of integrating a solid lying area.

Tail biting is a common problem in pigs kept in conventional fully slatted pens. Suitable enrichment materials can help to prevent the occurrence of this behavioural disorder by encouraging pigs to increase exploration behaviour. We investigated whether additional flavours can increase exploration behaviour in undocked pigs. Therefore, we offered straw pellets flavoured with either fried onion (FO), strawberry (SB), ginger, almond (AL), vanilla or without flavour (control) during rearing (eight groups in total) and fattening (16 groups in total). Flavoured pellets were offered in an altering order during intervals of 1 week in material dispensers. Exploration duration at the material dispensers was continuously recorded via an ultra-high-frequency radio-frequency identification system. Pigs were weighed weekly and their tail lengths and tail injuries were scored in four categories. For analysis, changes in tail length scores compared to the previous week were calculated as Δ-tail length. The different flavours affected pigs' exploration durations in both rearing (factor flavour, P < 0.0001) and fattening (factor flavour, P < 0.0001). Highest exploration durations during rearing were recorded when straw pellets were flavoured with FO and AL compared to all others. During fattening, exploration duration was highest towards controls without significant difference to SB. Exploration durations additionally were affected by temporal effects, i.e. week and day during rearing (both factors: P < 0.0001) and fattening (both factors: P < 0.0001). During rearing, highest exploration durations were recorded in the first week and on the first day within week after changing the flavour of the straw pellets. During fattening, exploration durations varied between weeks and within weeks. The highest durations were recorded at the end of weeks, i.e. on the fifth and seventh days after material change. During rearing, tail injuries were affected by week (P < 0.0001). From the fourth week of rearing, the prevalence of tail injuries significantly increased. During the fattening period, tail injuries were affected by flavour (P < 0.05). Fattening pigs had fewest tail injuries after straw pellets flavoured with AL were offered. Altogether, based on the exploration durations, rearing pigs showed different preferences for the flavoured straw pellets but highly explored flavours differed between rearing and fattening pigs. Despite a weekly change of the flavour of straw pellets, exploration durations decreased during rearing but increased again in the transition between rearing and fattening. Thus, straw pellets with alternating flavours are a suitable possibility to provide environmental enrichment to pigs but will not prevent tail biting.

Animal welfare labels have been introduced to improve housing conditions in conventional pig systems. Animal welfare should be increased by, e.g. offering a well-accepted and comfortable solid lying area. This study investigates the effect of bright light from an LED spotlight in the slatted area on lying and elimination behavior of fattening pigs. It was tested for two pen designs different in feeder and arrangement of the slatted area with 18 pigs per pen. The study took place in two different compartments (spatial repetition) with two pens of each pen design. The light intensity in the slatted area was increased by two spotlights within one pen of each design as case-control approach. A total of 648 fattening pigs were tested over four and five fattening periods respectively. The lying behavior was assessed by video scan sampling at three different weekdays at three times (morning, noon, evening) on each observation day. On average, the lying area was used by 60–63% of the pigs in the control pens and 67–69% in the spotlight pens. Additionally, a tendential effect of the deviation of the room temperature from the set temperature existed. The fouling of the animals and pen was not affected by the light intensity.

Tail biting is one of the biggest problems in pig production systems that causes animal welfare and economic problems. Therefore, tail docking is a widely used intervention to reduce tail biting. However, appropriate enrichment material that stimulates and increases exploration behaviour of pigs also reduces the prevalence and risk of tail biting. In 288 pigs with undocked tails we investigated whether the attractiveness of chopped straw (CS) as enrichment material can be further increased when maize kernels were added (CS+MK). Further, we examined whether a higher attractiveness is accompanied by reduced tail incidents. We used material dispensers equipped with ultra-high-frequency radio-frequency identification (UHF RFID) systems to record individual exploration times of the pigs to the offered enrichment materials. Furthermore, animals were scored thrice for tail length losses and tail injuries, i.e. after the rearing period, in the middle of the fattening period and at the end of the fattening period. Both rearing and fattening pigs had higher exploration durations when housed with CS+MK compared to CS (LME: rearing, P<0.001, fattening, P<0.05). Interestingly, enrichment materials not only remained interesting but were used even more from rearing to fattening. However, when CS+MK was offered pigs showed a higher prevalence for tail biting incidents in the rearing, but not in the fattening period, compared to CS (rearing GLMM, P<0.01). This may have resulted from competition for the more attractive enrichment material (CS+MK). An edible additive increased the interest for straw in pigs over long term but could not improve tail status.

A major problem in conventional pig production systems is the occurrence of abnormal behaviours such as tail biting. Tail biting is a multifactorial problem, but it seems that a lack of proper enrichment materials prevents the animals from performing normal species-specific behaviour, e.g., roofing, nosing or chewing, and thus increases the prevalence of tail biting. The aim of this study was to identify plant-based enrichment material and nutritive additives that are attractive to pigs and that can be used as enrichment in practice. Therefore, we carried out two choice tests to investigate (i) which plant-based enrichment materials, differing in structure and flavour, pigs prefer and (ii) what kind of nutritive additives can be used to further increase the attractiveness of plant-based enrichment materials. In each choice test, pigs had the choice of six offered options. Pigs were tested individually in their familiar environment in an arena for 150 s. The first choice test revealed that pelletized materials, i.e., lucerne pellets and straw pellets, were preferred over all other options tested (Friedman test, n = 55, p < 0.001). In the second choice test, the pigs' interest was highest for the largest nutritive additive, i.e., maize kernels, compared to the other options tested (Friedman test, n = 65, p < 0.001). When choosing enrichment materials for pigs, structure, size and flavour should be considered. Pelletized plant-based enrichment materials or non-pelletized materials with nutritive additives can be recommended to stimulate exploration. Further studies should examine the interval at which enrichment material needs to be altered to keep pigs' interest at a high level.

The main objective of this paper is the monitoring of daily activity patterns of fattening pigs at different locations in the housing environment using UHF-RFID. Four hundred fattening pigs were equipped with UHF-RFID ear tags and monitored during the fattening period for about four months. The RFID antennas were installed at the feeding troughs, playing devices and drinkers. A validation phase for each of these locations was carried out prior to the first data collection. The sensitivity (true positive rate) of the UHF-RFID system was about 80% at the feeding trough and the playing device and about 60% at the drinkers. The mean of the daily visiting time of all pigs at the trough was about 55 min. The mean visiting duration at the playing device was about 38 min and at the drinkers about 9 min. The visiting times of the pigs showed a high intra- and inter-variability. It was observed that the average visit duration at the feeding trough decreases over the course of a fattening period but increases at the playing device. A documentation of visiting times of animals is possible utilizing RFID systems, allowing a higher data density than video or direct observations.

Prior livestock research provides evidence for the importance of accurate detection of pig positions and postures for better understanding animal welfare. Position and posture detection can be accomplished by machine vision systems. However, current machine vision systems require rigid setups of fixed vertical lighting, vertical top-view camera perspectives or complex camera systems, which hinder their adoption in practice. Moreover, existing detection systems focus on specific pen contexts and may be difficult to apply in other livestock facilities. Our main contribution is twofold: First, we design a deep learning system for position and posture detection that only requires standard 2D camera imaging with no adaptations to the application setting. This deep learning system applies the state-of-the-art Faster R-CNN object detection pipeline and the state-of-the-art Neural Architecture Search (NAS) base network for feature extraction. Second, we provide a labelled open access dataset with 7277 human-made annotations from 21 standard 2D cameras, covering 31 different one-hour long video recordings and 18 different pens to train and test the approach under realistic conditions. On unseen pens under similar experimental conditions with sufficient similar training images of pig fattening, the deep learning system detects pig position with an Average Precision (AP) of 87.4%, and pig position and posture with a mean Average Precision (mAP) of 80.2%. Given different and more difficult experimental conditions of pig rearing with no or little similar images in the training set, an AP of over 67.7% was achieved for position detection. However, detecting the position and posture achieved a mAP between 44.8% and 58.8% only. Furthermore, we demonstrate exemplary applications that can aid pen design by visualizing where pigs are lying and how their lying behavior changes through the day. Finally, we contribute open data that can be used for further studies, replication, and pig position detection applications.

Increasing demands on animal welfare and the higher temperatures in summer due to climate change make it necessary to adapt conventional pig husbandry systems. A cooled, solid lying area has the potential to increase lying comfort and reduce the heat stress, which improves animal welfare. In the present study, the effect of a cooled, solid lying area on lying and elimination behavior was investigated. In two fattening compartments, eight pens with 28 pigs each were rebuilt. Two pen designs, different in feeder place and type, were tested. The floor was cooled from 24.5 to 20 °C by cool water in half of the pens. A total of 672 fattening pigs were tested over three fattening periods. The lying behavior was recorded by video analysis three times per week and three times per day. In the pens with a cooled lying area, 14% (SED 2.9; p = 0.002), respectively 12% (SED 0.9; p = 0.0382) more pigs were lying on the solid lying area. Additionally, the fouling of the animals was reduced by the cooling in one pen design; the results were derived from weekly scores (0.42 vs. 0.67; SED 0.058 p = 0.0006). The fouling of the pen was not affected by the floor cooling, however, the fouling in all pens was very low.

Automatic monitoring of animal feeding behaviour in commercial farms is desirable as it is an important indicator for the well-being and health of animals. Low-frequency and high-frequency radio frequency identification (RFID) systems have been tested for the detection of feeding visits of growing-finishing pigs, but the suitability of ultra-high frequency (UHF) RFID for this application has not yet been shown. Therefore, the objective of this study was the validation of a UHF-RFID system, consisting of a reader, antennas and passive transponder ear tags, for the monitoring of visits of growing-finishing pigs at a short trough for liquid feeding. Consequently, (1) two antenna variants (free-form and patch antennas) were tested at different levels of antenna output power, (2) two methods to determine a bout criterion for the creation of trough visits from the RFID registrations were compared, and (3) a comparison of the RFID data with reference data from video observation was carried out. The analysis showed that the reading area exceeded the trough especially in the variants with high output power. Thus, the evaluation of the first and second rate of change of the total daily number and total daily duration of visits led to higher values for the bout criterion (50 s for both antenna variants) than the evaluation of the mean absolute deviation between video and RFID data (20 s for the free-form antenna and 30 s for the patch antennas). The trough visits observed were detected best with the patch antennas at 25 dBm output power and a bout criterion of 30 s with regard to average precision (61.1%), and correlation between the video data and RFID visits (R-2 = 0.87 for total number and 0.80 for total duration of visits). The average sensitivity of this variant was 49.7%, specificity 99.0% and accuracy 97.9%. The highest average sensitivity (79.7%) and a good correlation between video data and RFID visits (R-2 = 0.78 for total number, 0.56 for total duration of visits with a bout criterion of 50 s) were measured with the free-form antenna at 26 dBm. In conclusion, UHF-RFID can be suitable for the monitoring of trough visits of growing-finishing pigs, but the effect of ear tissue on the performance of the UHF-RFID ear tags should be reduced by further development. In addition, further research should be carried out to evaluate the potential of this technology completely for animal behaviour monitoring.

Analyzing animals' behavior can lead to conclusions on their health status. The objectives of this paper are 1) to monitor the behavior of growing-finishing pigs throughout the fattening period with an ultra-high frequency radio frequency identification system (UHF-RFID) and 2) to detect lameness of individual animals with a calculated measure of activity, so-called "virtual walking distances". The RFID system consisted of UHF readers and antennas at specific hotspots in the pen, as well as UHF transponder ear tags for each pig and a software for data processing. For this study, 300 pigs were monitored with the RFID system over three fattening periods. The pigs were visually examined for their health condition twice a week. The "virtual walking distances" were calculated from the visiting order of the different hotspots and the distances between them. Because of the high variability of the daily virtual walking distance between different pigs, this measure has to be regarded individually for each pig to detect a beginning or ongoing lameness. For this purpose, a linear moving window regression model was tested on the data of the 300 pigs in this study. Lameness events, which were associated with a major difference between predicted and actual value, were detected by the model for 32% of the actual lame pigs. In other lameness cases, a drop of the graph in general was visible. Unfortunately, about 45% of the pigs with a severe lameness were not detectable due to a lack of change in virtual walking distance. In the next step, several adjustments and additions to the model will be tested to improve the detection rate of lameness events.