Season influence on 3,5,3’ triidothyronine (T3), tyroxine (T4) and testosterone (Tes) serum concentration

• Autor(a) principal: Barbosa, Orlando Rus
• Data de Publicação: 2008
• Outros Autores: Tutida, Leira, Hubler, Márcia Rosangela Neves de Oliveira, Akimoto, Luciene Setuko, Moraes, Gentil Vanini de
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Acta Scientiarum. Animal Sciences (Online)
• Texto Completo: https://periodicos.uem.br/ojs/index.php/ActaSciAnimSci/article/view/4344
• topic: estação do ano; hormônios tireóide; ovinos; sangue; testosterona; 5.04.00.00-2 Zootecnia

The serum concentration of 3,5,3’triiodothyronine (T3), tyroxine (T4) and testosterone (Tes) was studied, from March 1996 to March 1997, in 24 three-year-old rams. Three breeds were used: Bergamacia breed, nine animals (Be), eighth Corriedale (Co) and seven Hampshire Down (Hd). The blood was collected each 30 days, as well as the meteorolgical data: wind speed (v), air temperature (Ta), globe temperature (Tg) and relative humidity (Ur). Corriedale animals presented increasing values of T3 from March (0.27ng.ml-1) to December (0.99ng.ml-1), decreasing in January (0.11ng.ml-1), and returning to the March values (0.27ng.ml-1. There was no seasonal effect (P > 0.05) on T3 concentration for the breeds Be (0.17ng.ml-1) and Hd (0.57ng.ml-1). As for T4, the Corriedade had lower values from March (7.67ng.ml-1) to August (3.92ng.ml-1), with higher ones in January (12.33ng.ml-1). Hampshire animals presented increased T4 concentration from March (3.54ng.ml-1) to October (5.61ng.ml-1), decreasing until January (2.16ng.ml-1) (summer). For the Bergamacia there was a decrease of T4 in March (4.73ng.ml-1) and after, with the lowest value in December (3.77ng.ml-1), and going up again in January (4.95ng.ml-1). Serum concentration of Tes was significant (P < 0,01) for Hd, being higher from March (2.38ng.ml-1) to December (6.75ng.ml-1), decreasing in January (1.41ng.ml-1), increasing again, and reaching March prior values (2.38ng.ml-1). There was no seasonal effect (P > 0,05) on the Tes for Be (4.15ng.ml-1) and Co (3.21ng.ml-1).