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Baier-Stegmaier S, Gundlach C, Chriél M, Hansen MS, Vedel-Smith C, Hansen CV, Johansson DK, Henriksen LB, Wahlberg M, Thøstesen CB, Alstrup AKO, Gregersen KM, Pertoldi C, Pagh S. Computed Tomography as a Method for Age Determination of Carnivora and Odontocetes with Validation from Individuals with Known Age. Animals (Basel) 2023; 13:1783. [PMID: 37889740 PMCID: PMC10251996 DOI: 10.3390/ani13111783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 05/19/2023] [Accepted: 05/24/2023] [Indexed: 10/29/2023] Open
Abstract
Traditional methods for age determination of wildlife include either slicing thin sections off or grinding a tooth, both of which are laborious and invasive. Especially when it comes to ancient and valuable museum samples of rare or extinct species, non-invasive methods are preferable. In this study, X-ray micro-computed tomography (µ-CT) was verified as an alternative non-invasive method for age determination of three species within the order of Carnivora and suborders Odontoceti. Teeth from 13 red foxes (Vulpes vulpes), 2 American mink (Neogale vison), and 2 harbor porpoises (Phocoena phocoena) of known age were studied using µ-CT. The number of visible dental growth layers in the µ-CT were highly correlated with true age for all three species (R2 = 96%, p < 0.001). In addition, the Bland-Altman plot showed high agreement between the age of individuals and visible dental layers represented in 2D slices of the 3D µ-CT images. The true age of individuals was on average 0.3 (±0.6 SD) years higher than the age interpreted by the µ-CT image, and there was a 95% agreement between the true age and the age interpreted from visible dental layers in the µ-CT.
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Affiliation(s)
- Sina Baier-Stegmaier
- Department of Physics, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; (S.B.-S.)
| | - Carsten Gundlach
- Department of Physics, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; (S.B.-S.)
| | - Mariann Chriél
- Department of Health Technology Center for Diagnostics, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Mette Sif Hansen
- Department of Health Technology Center for Diagnostics, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
- Department of Veterinary and Animal Sciences, University of Copenhagen, 1870 Frederiksberg C, Denmark
| | - Christina Vedel-Smith
- Department of Research and Collections, Natural History Museum Aarhus, 8000 Aarhus, Denmark; (C.V.-S.)
| | - Charlotte Vikkelsø Hansen
- Department of Research and Collections, Natural History Museum Aarhus, 8000 Aarhus, Denmark; (C.V.-S.)
| | | | | | - Magnus Wahlberg
- Marine Biological Research Center, University of Southern Denmark, 5300 Kerteminde, Denmark
| | | | - Aage Kristian Olsen Alstrup
- Department of Clinical Medicine, Aarhus University, 8200 Aarhus, Denmark
- Department for Nuclear Medicine & PET, Aarhus University Hospital, 8200 Aarhus, Denmark
| | | | - Cino Pertoldi
- Department of Chemistry and Bioscience—Section of Biology and Environmental Science, Aalborg University, 9220 Aalborg, Denmark
| | - Sussie Pagh
- Department of Chemistry and Bioscience—Section of Biology and Environmental Science, Aalborg University, 9220 Aalborg, Denmark
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Sengupta ME, Pagh S, Stensgaard AS, Chriel M, Petersen HH. Prevalence of Toxoplasma gondii and Cryptosporidium in Feral and Farmed American Mink (Neovison vison) in Denmark. Acta Parasitol 2021; 66:1285-1291. [PMID: 33977399 DOI: 10.1007/s11686-021-00409-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 04/28/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE To investigate the prevalence of Cryptosporidium spp. infection and Toxoplasma gondii antibodies in farmed and feral mink in Denmark. METHODS We examined meat juice from 235 feral mink and 306 farmed mink for T. gondii antibodies, and faecal samples from 113 feral mink and 166 farmed mink for Cryptosporidium oocyst excretion. Meat juice was analysed using a commercial indirect enzyme-linked immunosorbent assay and oocyst excretion was identified by a modified Ziehl-Neelsen method. RESULTS All farmed mink tested sero-negative, while 53.6% of feral mink were T. gondii sero-positive. The probability of being sero-positive for T. gondii was not associated with recent escapes from farms (p = 0.468), but was significantly higher for male feral mink (64.2%) than female feral mink (42.5%) (p = 0.0008). Only one feral mink and four farmed mink (2.4%) excreted Cryptosporidium oocysts. CONCLUSION Farmed mink were all T. gondii sero-negative, whereas approximately half the feral mink were sero-positive. Cryptosporidium prevalence in farmed and feral mink were low. Overall, the public health risk of transmission of these two parasites via mink in Denmark is low.
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Pagh S, Pertoldi C, Chriel M, Petersen HH, Jensen TH, Madsen S, Kraft DCE, Schou TM, Hansen MS. Estimation of the Age and Reproductive Performance of Wild-Born and Escaped Mink ( Neovison vison) Caught in the Wild in Denmark. Animals (Basel) 2021; 11:ani11010162. [PMID: 33445630 PMCID: PMC7827876 DOI: 10.3390/ani11010162] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 01/07/2021] [Accepted: 01/10/2021] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Previous studies of wild caught mink in Denmark showed that 30–80% had recently escaped from farms. Therefore, it is debated whether a self-sustaining feral mink population is established in Denmark or whether the population rests upon a continuous contribution of captive-born farm mink. Knowledge regarding the reproduction and mortality of mink adapted for living in the wild is important for the management of feral mink. In this study, we separated wild-born from captive-born mink caught in the wild in Denmark. To be able to age the mink in this study, an age determination model for mink was developed based on the width of the pulp cavity. The mean litter size of wild-born female mink was 7.6 (range: 5–11 kits). The annual turnover of mink caught in the wild was estimated to be 66%, and the yearly mortality was 69%; thus, the population of wild-born mink is slightly declining. The results confirmed that the wild-born mink population in Denmark is reproducing and self-sustaining without a continuous influx of captive-born mink escaped from farms. The effect of escaped mink on the wild mink population will depend on the currently unknown ability of captive mink to survive in the wild. Abstract The feral mink population in Denmark consists of two groups of animals: mink born in the wild and mink that have recently escaped from farms. The aims of this study were to: (1) estimate the reproductive performance and mortality of the Danish mink born in the wild (wild-born) and mink escaped from farms (captive-born); (2) discuss the likelihood of a self-sustaining population of wild-born mink in Denmark; and (3) model the relationship between the pulp cavity width and the age of mink. During 2018, 247 wild caught mink were sent for necropsy at the Danish National Veterinary Institute. Based on body length, 112 were determined as captive-born and 96 as wild-born. The mean litter size ± SE of wild-born females was 7.6 ± 0.9 (range: 5–11 kits) and for captive-born females 5.9 ± 0.9 (range: 1–10 kits). The relationship between age (in months) of mink and pulp cavity width was highly significant. Individuals with a pulp cavity width of >35% were younger than one year. Based on fecundity, the turnover of the mink population was estimated to be 66%, and the yearly mortality was estimated at 69%. Hence, the population is slightly declining. In conclusion, a feral reproducing mink population in Denmark persists without a continuous influx of captive-born mink from farms.
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Affiliation(s)
- Sussie Pagh
- Department of Chemistry and Bioscience—Section of Biology and Environmental Science, Aalborg University, Fredrik Bajers Vej 7, 9220 Aalborg, Denmark; (C.P.); (T.H.J.); (T.M.S.)
- Correspondence:
| | - Cino Pertoldi
- Department of Chemistry and Bioscience—Section of Biology and Environmental Science, Aalborg University, Fredrik Bajers Vej 7, 9220 Aalborg, Denmark; (C.P.); (T.H.J.); (T.M.S.)
- Aalborg Zoo, Mølleparkvej 63, 9000 Aalborg, Denmark
| | - Mariann Chriel
- National Veterinary Institute, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark; (M.C.); (H.H.P.)
| | - Heidi Huus Petersen
- National Veterinary Institute, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark; (M.C.); (H.H.P.)
| | - Trine Hammer Jensen
- Department of Chemistry and Bioscience—Section of Biology and Environmental Science, Aalborg University, Fredrik Bajers Vej 7, 9220 Aalborg, Denmark; (C.P.); (T.H.J.); (T.M.S.)
- Aalborg Zoo, Mølleparkvej 63, 9000 Aalborg, Denmark
| | - Sussi Madsen
- Department of Dentistry and Oral Health, University of Aarhus, Vennelyst Boulevard 9, 8000 Aarhus C, Denmark; (S.M.); (D.C.E.K.)
| | - David Chr. Evar Kraft
- Department of Dentistry and Oral Health, University of Aarhus, Vennelyst Boulevard 9, 8000 Aarhus C, Denmark; (S.M.); (D.C.E.K.)
| | - Toke Munk Schou
- Department of Chemistry and Bioscience—Section of Biology and Environmental Science, Aalborg University, Fredrik Bajers Vej 7, 9220 Aalborg, Denmark; (C.P.); (T.H.J.); (T.M.S.)
| | - Mette Sif Hansen
- Sektion of Pathobiology, University of Copenhagen, Ridebanevej 3, 1870 Frederiksberg C, Denmark;
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