Piling behaviour in Swiss layer flocks: Description and related factors

Smothering is a major concern within the Swiss layer industry as it can lead to a high number of animal losses. The underlying cause is piling behaviour (PB), a phenomenon where hens densely cluster together in the litter area. The aim of this study was to describe PB and events preceding PB. Furthermore, we investigated the relation of the number of piles, pile duration, and number of hens involved in a pile with time of day, flock colour, flock age, environmental factors, and flock responses to behaviour tests. We video recorded the corners of litter areas (floor) inside the barn and winter garden of 13 commercial Swiss layer flocks (5 white, 5 brown, 3 mixed layer hybrids), which were known to previously experienced problems with smothering. We recorded environmental data (air speed, spot temperature) in the observed corners and assessed flock-level responses to two behaviour tests (novel object test, stationary person test). From the video recordings, events preceding piling and piling characteristics were assessed at 20 and 30 weeks of age (w) at three times per day (0−5 h, >5-10 h, >10−15 h after lights on). Statistical analyses included generalized and linear mixed-effects models and Spearman correlations. Results showed that piling events were mainly preceded by single hen activities (77.9%) and non- hysterical mass movements (7.6%). More piles and the largest numbers of animals involved in piling occurred in white and brown flocks at >5−10 h after lights came on. The number of piles was lower and the number of involved animals and pile duration higher in 20 w compared to 30 w. No correlation was found between environmental factors and flock behaviour test responses with piling characteristics. Potential underlying causes for PB are numerous, though we provide and discuss likely mechanisms, including response facilitation, individual stimulus response, and anti-predation behaviour, based on our findings. Furthermore, PB could relate to diurnal behaviours, for example, dustbathing and hens laying floor eggs in the litter area

Effect of different management protocols for grouping does on aggression and dominance hierarchies

The study aimed at evaluating different management protocols of grouping does in regard to aggressive interactions and the establishment of a hierarchy under commercial conditions. Fifty-seven multiparous rabbit does of the Hycole hybrid maternal line were randomly distributed into three different management protocols (MP) for a total of 5 consecutive trials: MP12 with grouping 12 days after parturition, MP18 after 18 days and MP22 after 22 days. Video recordings were made during the first 24 h after grouping and after 6 and 10 days, and used to score aggressive interactions of the animals with exception of treatment 3 where day 10 was omitted because it was after the weaning of the kits. For MP12 and MP18 the frequency of different categories of aggressive interactions were significantly higher on the day of grouping than afterwards, with a strong decrease on day 6 (P < 0.02), but almost no change was found between days 6 and 10. This was especially true for biting, with a high frequency of occurrence just after grouping and a subsequent decrease on day 6 under all management schedules (P = 0.005). The change in the number of aggressive interactions between 6 and 10 days after grouping was not significantly different between MPs. However, the time point of 6 days after grouping seemed to be fundamental in reducing the number of aggressive events. Although a longer separation for 18 and 22 days after parturition did not reduce the total number of aggressive interactions, MP18 and MP22 showed more mild aggressive interactions with respect to MP12 on the day of regrouping. Moreover, when comparing MPs concerning the development of hierarchy, hierarchies appeared very stable independently of the length of grouping (P < 0.01)

Similarity in Temporal Movement Patterns in Laying Hens Increases with Time and Social Association.

We explored the relationship between social associations and individual activity patterns in domestic hens. Out of 1420 laying hens, 421 hens were equipped with RFID tags attached to RFID-specific leg bands (leg bands from Company Roxan, Selkirk, Scotland) to continuously track their change in location across four different areas (one indoor and three outdoor areas). Using a combination of social network analysis for quantifying social relationships and dynamic time warping for characterizing the movement patterns of hens, we found that hens were consistent in their individual variation in temporal activity and maintained stable social relationships in terms of preferred association partners. In addition to being consistent, social associations correlated with movement patterns and this correlation strengthened over the period of observation, suggesting that the animals aligned their activity patterns with those of their social affiliates. These results demonstrate the importance of social relationships when considering the expression of individual behaviour. Notably, differences in temporal patterns emerge despite rather homogeneous rearing conditions, same environment, and low genetic diversity. Thus, while variation in behavioural phenotypes can be observed across isolated individuals, this study shows that the social environment within a group can shape and enhance variation in general movement patterns of individual animals

Mechanical design of the optical modules intended for IceCube-Gen2

IceCube-Gen2 is an expansion of the IceCube neutrino observatory at the South Pole that aims to increase the sensitivity to high-energy neutrinos by an order of magnitude. To this end, about 10,000 new optical modules will be installed, instrumenting a fiducial volume of about 8 km3. Two newly developed optical module types increase IceCube’s current sensitivity per module by a factor of three by integrating 16 and 18 newly developed four-inch PMTs in specially designed 12.5-inch diameter pressure vessels. Both designs use conical silicone gel pads to optically couple the PMTs to the pressure vessel to increase photon collection efficiency. The outside portion of gel pads are pre-cast onto each PMT prior to integration, while the interiors are filled and cast after the PMT assemblies are installed in the pressure vessel via a pushing mechanism. This paper presents both the mechanical design, as well as the performance of prototype modules at high pressure (70 MPa) and low temperature (−40∘C), characteristic of the environment inside the South Pole ice

Direction reconstruction performance for IceCube-Gen2 Radio

The IceCube-Gen2 facility will extend the energy range of IceCube to ultra-high energies. The key component to detect neutrinos with energies above 10 PeV is a large array of in-ice radio detectors. In previous work, direction reconstruction algorithms using the forward-folding technique have been developed for both shallow (≲20 m) and deep in-ice detectors, and have also been successfully used to reconstruct cosmic rays with ARIANNA. Here, we focus on the reconstruction algorithm for the deep in-ice detector, which was recently introduced in the context of the Radio Neutrino Observatory in Greenland (RNO-G)

Deep Learning Based Event Reconstruction for the IceCube-Gen2 Radio Detector

The planned in-ice radio array of IceCube-Gen2 at the South Pole will provide unprecedented sensitivity to ultra-high-energy (UHE) neutrinos in the EeV range. The ability of the detector to measure the neutrino’s energy and direction is of crucial importance. This contribution presents an end-to-end reconstruction of both of these quantities for both detector components of the hybrid radio array (\u27shallow\u27 and \u27deep\u27) using deep neural networks (DNNs). We are able to predict the neutrino\u27s direction and energy precisely for all event topologies, including the electron neutrino charged-current (νe-CC) interactions, which are more complex due to the LPM effect. This highlights the advantages of DNNs for modeling the complex correlations in radio detector data, thereby enabling a measurement of the neutrino energy and direction. We discuss how we can use normalizing flows to predict the PDF for each individual event which allows modeling the complex non-Gaussian uncertainty contours of the reconstructed neutrino direction. Finally, we discuss how this work can be used to further optimize the detector layout to improve its reconstruction performance

The next generation neutrino telescope: IceCube-Gen2

The IceCube Neutrino Observatory, a cubic-kilometer-scale neutrino detector at the geographic South Pole, has reached a number of milestones in the field of neutrino astrophysics: the discovery of a high-energy astrophysical neutrino flux, the temporal and directional correlation of neutrinos with a flaring blazar, and a steady emission of neutrinos from the direction of an active galaxy of a Seyfert II type and the Milky Way. The next generation neutrino telescope, IceCube-Gen2, currently under development, will consist of three essential components: an array of about 10,000 optical sensors, embedded within approximately 8 cubic kilometers of ice, for detecting neutrinos with energies of TeV and above, with a sensitivity five times greater than that of IceCube; a surface array with scintillation panels and radio antennas targeting air showers; and buried radio antennas distributed over an area of more than 400 square kilometers to significantly enhance the sensitivity of detecting neutrino sources beyond EeV. This contribution describes the design and status of IceCube-Gen2 and discusses the expected sensitivity from the simulations of the optical, surface, and radio components

Sensitivity of IceCube-Gen2 to measure flavor composition of Astrophysical neutrinos

The observation of an astrophysical neutrino flux in IceCube and its detection capability to separate between the different neutrino flavors has led IceCube to constraint the flavor content of this flux. IceCube-Gen2 is the planned extension of the current IceCube detector, which will be about 8 times larger than the current instrumented volume. In this work, we study the sensitivity of IceCube-Gen2 to the astrophysical neutrino flavor composition and investigate its tau neutrino identification capabilities. We apply the IceCube analysis on a simulated IceCube-Gen2 dataset that mimics the High Energy Starting Event (HESE) classification. Reconstructions are performed using sensors that have 3 times higher quantum efficiency and isotropic angular acceptance compared to the current IceCube optical modules. We present the projected sensitivity for 10 years of data on constraining the flavor ratio of the astrophysical neutrino flux at Earth by IceCube-Gen2