Janja Sirovnik

Dr. Janja Sirovnik

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Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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30 July 2020 in Journal of Dairy Research
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JSJanja Sirovnik
Janja Sirovnik
KBKerstin Barth
Kerstin Barth
DODaiana de Oliveira
Daiana de Oliveira
SFSabine Ferneborg
Sabine Ferneborg
MHMarie J. Haskell
Marie J. Haskell
JJJulie Føske Johnsen
Julie Føske Johnsen
Due to increasing public concern regarding separation of the dairy cow and calf within the first days after birth, alternative systems, where cows and calves stay in contact for an extended period, are receiving increasing interest from a broad array of researchers and other stakeholders. With more research in the area, there is a risk of inconsistencies emerging in the use of terminology. To create a better consensus in further discussions, the aim of this Research Reflection is to provide definitions and propose a common terminology for cow-calf contact in dairy production. We also suggest definitions for various systems allowing cow-calf contact and describe the distinct phases of cow-calf contact systems.

1 January 2018 in Applied Animal Behaviour Science
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Journal Article
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JSJanja Sirovnik
Janja Sirovnik
HWHanno Würbel
Hanno Würbel
MTMichael J. Toscano
Michael J. Toscano

7 August 2020 in Journal of Dairy Research
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NSNoemi Kim Santo
Noemi Kim Santo
UBUta König v. Borstel
Uta König v. Borstel
JSJanja Sirovnik
Janja Sirovnik
The study reported in this research communication aimed to assess the influence of maternal contact on calves' activity, fearfulness, and social competence. Calves were either dam-reared for their first 14 d of age (Maternal Contact, n = 12) or were separated from their dams within 12 h after birth (Motherless, n = 12). Calves of both treatments and the dams of Maternal Contact calves were group-housed and suckling was prevented with udder nets. The general activity (lying, locomotion, swapping between lying and standing) was measured using pedometers in eight Maternal Contact and eight Motherless calves within a 24-d period. Since general activity might be affected by calves' age or the separation of Maternal Contact calves from the dams the 24-d period was additionally divided into two groups (period A: 3rd–13th day of age, period B: 14th–27th day of age). Emotionality and social competence were assessed in the open field, novel object, and confrontation test with an unknown cow at 14, 21, and 28 d of age, respectively. Mann–Whitney-U-tests were performed for statistical analysis. Locomotion was greater in Motherless calves than Maternal Contact calves during the 24-d period (A + B combined, P < 0.001) and period B (14th to 27th day of age, P < 0.001). There was no treatment difference in duration of lying or in the amount of swapping in any of the periods. After a Bonferroni correction, which we used due to the exploratory character of the study, there were no treatment differences in behaviours indicating emotionality. Compared to Motherless calves, Maternal Contact calves showed increased vigilance (P < 0.01) during the confrontation test. The results of this study indicate that mother-reared calves likely searched less for social contact and developed greater social skills than calves that were separated from their mothers soon after birth.

16 May 2022 in Animals
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JSJanja Sirovnik
Janja Sirovnik
ARAnja B Riber
Anja B Riber
Dark brooders, i.e., horizontal heating elements for chicks equipped with curtains, mimic some aspects of maternal care, such as the provision of heat and a dark area for chicks to rest. Thus, they can be considered as artificial passive replacements of a mother hen. Despite their advantages in animal welfare and the likely positive outcomes in production and economy, dark brooders are rarely used in commercial layer pullet facilities. The main positive effect on welfare is a reduction of injurious pecking during the rearing and laying periods, which results in improved feather cover and reduced skin injuries and mortality due to cannibalism. Other welfare benefits include improved rest in dark-brooded chicks and reduced fearfulness at all ages tested (i.e., from 4 to 26 weeks). The impact on production and economy is seen in a reduction of the energy costs in the first weeks of life due to radiant heating, as well as improved total egg production and reduced floor egg laying. The aim of this paper is to review the existing literature on the effects of dark brooders on injurious pecking and other welfare issues in layers, including speculations on the possible explanations for improved welfare. We also discuss the possible reasons for why dark brooders are not applied more commonly in commercial practice, including insufficient information on the economic aspects of using brooders and the lack of commercially available brooder options.

19 January 2021 in Behavioral Ecology and Sociobiology
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JSJanja Sirovnik
Janja Sirovnik
BVBernhard Voelkl
Bernhard Voelkl
LKLinda Jane Keeling
Linda Jane Keeling
HWHanno Würbel
Hanno Würbel
MTMichael Jeffrey Toscano
Michael Jeffrey Toscano
Under the ideal free distribution (IFD), the number of organisms competing for a resource at different sites is proportional to the resource distribution among sites. The ideal free distribution of competitors in a heterogeneous environment often predicts habitat matching, where the relative number of individuals using any two patches matches the relative availability of resources in those same two patches. If a resource is scarce, access might be restricted to individuals with high resource holding potential, resulting in deviation from the IFD. The distribution of animals may also deviate from the IFD in the case of resource abundance, when social attraction or preference for specific locations rather than competition may determine distribution. While it was originally developed to explain habitat choice, we apply the habitat matching rule to microscale foraging decisions. We show that chickens feeding from two nondepleting feeders distribute proportionally to feeder space under intermediate levels of competition. However, chicken distribution between the feeders deviates from the IFD when feeder space is limited and competition high. Further, despite decreasing aggression with increasing feeder space, deviation from IFD is also observed under an excess supply of feeder space, indicating different mechanisms responsible for deviations from the IFD. Besides demonstrating IFD sensitivity to competition, these findings highlight IFD’s potential as a biological basis for determining minimal resource requirements in animal housing. Significance statement: The ideal free distribution (IFD) predicts how animals ought to distribute themselves within a habitat in order to maximize their payoff. Recent studies, however, have questioned the validity of the IFD concept following anomalous results. We studied the IFD in chickens by systematically varying the amount and distribution of space at two feed troughs. We show that when tested over a sufficiently large range, the distribution of birds depends on the overall resource availability. Furthermore, behavioral data suggest that distinctly different mechanisms account for deviations from the IFD at shortage and excess supply of feeder space, respectively.

6 April 2022 in British Poultry Science
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Journal Article
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MKMaria-Elisabeth Krautwald-Junghanns
Maria-Elisabeth Krautwald-Junghanns
JSJanja Sirovnik
Janja Sirovnik
Worldwide, there are various regulations and recommendations on the maximum stocking density. While stocking density can be determined based on the space covered by the body, a more appropriate method considers space requirements for natural behaviour. Turkeys are less likely disturbed at low stocking density as seen by increased sitting, lying, and preening behaviours, compared to animals housed at high stocking density. Furthermore, lower stocking density, together with smaller group size, species-appropriate light conditions and suitable structuring of barn housing, have been repeatedly mentioned as good strategies to prevent injurious pecking. Increased stocking density – in terms of weight and animal number per floor area – is related to increased litter moisture, which can have negative impact on animal welfare. High stocking density can lead to poor body mass gain and increased mortality, which are indicators of impaired welfare and economic losses. Based on the available scientific literature and economic aspects with regard to the above criteria, maximum stocking density for turkeys appears to be 40 kg live weight per m2 of usable floor space. However, the number of animals per square space should be limited to avoid increased litter moisture and reduced health and welfare.