Serum testosterone concentrations, testicular biometry, and testicular tone in wild male lowland tapirs (Tapirus terrestris) in the Pantanal and Cerrado biomes, Brazil
abstract: This study aimed to contribute to the knowledge about the reproductive physiology of wild lowland tapirs (Tapirus terrestris) by describing the serum testosterone concentrations, testicular biometry, and testicular tone of individuals living in the Pantanal and Cerrado biomes of Brazil, an...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2022-01-01
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| Series: | Theriogenology Wild |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2773093X22000058 |
| _version_ | 1797866935583506432 |
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| author | Andreza V. Brasil Felipe Z. Brandão Emília P. Medici Alexandre R. Silva |
| author_facet | Andreza V. Brasil Felipe Z. Brandão Emília P. Medici Alexandre R. Silva |
| author_sort | Andreza V. Brasil |
| collection | DOAJ |
| description | abstract: This study aimed to contribute to the knowledge about the reproductive physiology of wild lowland tapirs (Tapirus terrestris) by describing the serum testosterone concentrations, testicular biometry, and testicular tone of individuals living in the Pantanal and Cerrado biomes of Brazil, and to check for reproductive seasonality for the species, and to investigate correlations among these reproductive parameters and individual age and weight. Meteorological data (air temperature, wind speed, relative humidity, and global radiation) of the study sites were characterized through automated stations of the National Institute of Meteorology (INMET). From 2015–2020, field data were collected from 22 and 11 wild male lowland tapirs from the Pantanal and Cerrado biomes, respectively. After capture and chemical restraint, the age and weight of the animals were estimated. Blood samples were collected to determine serum testosterone concentrations using radioimmunoassay. Testicular biometry measurements included width, length, height, and volume, while testicular tone was assigned using scores from 3 (firm) to 1 (soft). Animal age, weight, and testosterone concentrations did not differ between the two biomes (P > 0.05). Positive correlations were found between age and weight (ρ = 0.86; P < 0.001), and serum testosterone levels with both estimated age (ρ = 0.45; P = 0.0047) and weight (ρ = 0.51; P = 0.0011). Testicular volume was positively correlated with age (ρ = 0.75; P < 0.0001), weight (ρ = 0.65; P = 0.0011), and serum testosterone levels (ρ = 0.42; P = 0.0081). In addition, testicular tone in adult subjects (>48 months) was significantly higher than in younger subjects (P < 0.05). Testicular consistency was positively correlated with weight (ρ = 0.36; P = 0.0241) and serum testosterone levels (ρ = 0.38; P = 0.0174). Seasonal effect on tapir reproduction was not identified, but testicular tone was influenced by wind speed (ρ = 0.37; P = 0.0211) and air humidity (ρ = 0.37; P = 0.0262). This study is the first scientific description of reproductive parameters of male lowland tapirs. |
| first_indexed | 2024-04-09T23:32:12Z |
| format | Article |
| id | doaj.art-c1a0a376cda84d89a39813ae9cc5e2ae |
| institution | Directory Open Access Journal |
| issn | 2773-093X |
| language | English |
| last_indexed | 2024-04-09T23:32:12Z |
| publishDate | 2022-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Theriogenology Wild |
| spelling | doaj.art-c1a0a376cda84d89a39813ae9cc5e2ae2023-03-21T04:17:28ZengElsevierTheriogenology Wild2773-093X2022-01-011100005Serum testosterone concentrations, testicular biometry, and testicular tone in wild male lowland tapirs (Tapirus terrestris) in the Pantanal and Cerrado biomes, BrazilAndreza V. Brasil0Felipe Z. Brandão1Emília P. Medici2Alexandre R. Silva3Laboratory for Animal Germplasm Conservation, Department of Animal Sciences, Federal University of the Semiarid Region, UFERSA, Mossoró, Rio Grande do Norte, BrazilFaculty of Veterinary, Fluminense Federal University, UFF, Niterói, Rio de Janeiro, BrazilIUCN SSC Tapir Specialist Group (TSG), Mato Grosso do Sul, Brazil; Lowland Tapir Conservation Initiative (LTCI), Instituto de Pesquisas Ecológicas (IPÊ), Campo Grande, Mato Grosso do Sul, Brazil; Escola Superior de Conservação Ambiental e Sustentabilidade (ESCAS/IPÊ), Nazaré Paulista, São Paulo, BrazilLaboratory for Animal Germplasm Conservation, Department of Animal Sciences, Federal University of the Semiarid Region, UFERSA, Mossoró, Rio Grande do Norte, Brazil; Corresponding author.abstract: This study aimed to contribute to the knowledge about the reproductive physiology of wild lowland tapirs (Tapirus terrestris) by describing the serum testosterone concentrations, testicular biometry, and testicular tone of individuals living in the Pantanal and Cerrado biomes of Brazil, and to check for reproductive seasonality for the species, and to investigate correlations among these reproductive parameters and individual age and weight. Meteorological data (air temperature, wind speed, relative humidity, and global radiation) of the study sites were characterized through automated stations of the National Institute of Meteorology (INMET). From 2015–2020, field data were collected from 22 and 11 wild male lowland tapirs from the Pantanal and Cerrado biomes, respectively. After capture and chemical restraint, the age and weight of the animals were estimated. Blood samples were collected to determine serum testosterone concentrations using radioimmunoassay. Testicular biometry measurements included width, length, height, and volume, while testicular tone was assigned using scores from 3 (firm) to 1 (soft). Animal age, weight, and testosterone concentrations did not differ between the two biomes (P > 0.05). Positive correlations were found between age and weight (ρ = 0.86; P < 0.001), and serum testosterone levels with both estimated age (ρ = 0.45; P = 0.0047) and weight (ρ = 0.51; P = 0.0011). Testicular volume was positively correlated with age (ρ = 0.75; P < 0.0001), weight (ρ = 0.65; P = 0.0011), and serum testosterone levels (ρ = 0.42; P = 0.0081). In addition, testicular tone in adult subjects (>48 months) was significantly higher than in younger subjects (P < 0.05). Testicular consistency was positively correlated with weight (ρ = 0.36; P = 0.0241) and serum testosterone levels (ρ = 0.38; P = 0.0174). Seasonal effect on tapir reproduction was not identified, but testicular tone was influenced by wind speed (ρ = 0.37; P = 0.0211) and air humidity (ρ = 0.37; P = 0.0262). This study is the first scientific description of reproductive parameters of male lowland tapirs.http://www.sciencedirect.com/science/article/pii/S2773093X22000058WildlifeMegafaunaPerissodactylaUngulateReproductionHormone measurement |
| spellingShingle | Andreza V. Brasil Felipe Z. Brandão Emília P. Medici Alexandre R. Silva Serum testosterone concentrations, testicular biometry, and testicular tone in wild male lowland tapirs (Tapirus terrestris) in the Pantanal and Cerrado biomes, Brazil Theriogenology Wild Wildlife Megafauna Perissodactyla Ungulate Reproduction Hormone measurement |
| title | Serum testosterone concentrations, testicular biometry, and testicular tone in wild male lowland tapirs (Tapirus terrestris) in the Pantanal and Cerrado biomes, Brazil |
| title_full | Serum testosterone concentrations, testicular biometry, and testicular tone in wild male lowland tapirs (Tapirus terrestris) in the Pantanal and Cerrado biomes, Brazil |
| title_fullStr | Serum testosterone concentrations, testicular biometry, and testicular tone in wild male lowland tapirs (Tapirus terrestris) in the Pantanal and Cerrado biomes, Brazil |
| title_full_unstemmed | Serum testosterone concentrations, testicular biometry, and testicular tone in wild male lowland tapirs (Tapirus terrestris) in the Pantanal and Cerrado biomes, Brazil |
| title_short | Serum testosterone concentrations, testicular biometry, and testicular tone in wild male lowland tapirs (Tapirus terrestris) in the Pantanal and Cerrado biomes, Brazil |
| title_sort | serum testosterone concentrations testicular biometry and testicular tone in wild male lowland tapirs tapirus terrestris in the pantanal and cerrado biomes brazil |
| topic | Wildlife Megafauna Perissodactyla Ungulate Reproduction Hormone measurement |
| url | http://www.sciencedirect.com/science/article/pii/S2773093X22000058 |
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