Pizzutto Cristiane S, Corrêa Sandra H R, Teixeira Rodrigo H F, Rosenfield Derek A, Jorge Neto Pedro Nacib, Berbare Patrícia, Rodriguez Erika G, Oliveira Claudio A
Department of Animal Reproduction, Faculty of Veterinary Medicine and Animal Science, University of São Paulo (USP), São Paulo, Brazil.
Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso (UFMT), Cuiaba, Brazil.
Zoo Biol. 2019 Aug;38(4):355-359. doi: 10.1002/zoo.21489. Epub 2019 May 6.
The fallow deer (Dama dama) is a species of Cervidae commonly kept in captivity, either in commercial farms or in zoos. The reproductive seasonality of this species is well known in the northern hemisphere, where photoperiod is a decisive factor in androgenic activity and, consequently, in the development of secondary sexual characteristics among male adults. The maintenance of this species in tropical regions has been successful, but there are no studies that demonstrate the maintenance of reproductive seasonality under these climatic conditions, which was the objective of the present study. To do so, the present investigation involved 27 fallow deer (D. dama) specimens, of which 14 were adults and 13 prepubescent (<8 months) individuals, all assessed during and outside (December-February) the reproductive season (June-August). The serum concentrations of testosterone, testicular volume, and neck circumference were analyzed among all animals during both seasons. The reproductive season was marked by expressive hormonal concentrations, increasing neck circumference and testicular volume, differing significantly between adults and prepubescent individuals outside the season. Positive correlations were observed among all analyzed variables: mean testicular volume and neck circumference (r = 0.92, p < 0.0001), testicular volume and testosterone concentrations (r = 0.79, p < 0.0001) and between neck circumference and testosterone concentrations (r = 0.67, p < 0.0001). Given the results found, the conclusion is that even under tropical climate conditions the reproductive seasonality of the fallow deer is well defined and may be related to photoperiod.
黇鹿（Dama dama）是鹿科的一种动物，通常饲养在商业养殖场或动物园中。该物种的繁殖季节性在北半球是众所周知的，在那里光周期是雄激素活性的决定性因素，因此也是成年雄性第二性征发育的决定性因素。该物种在热带地区的饲养已经取得成功，但尚无研究表明在这些气候条件下繁殖季节性能够维持，而这正是本研究的目的。为此，本调查涉及27只黇鹿（D. dama）标本，其中14只为成年鹿，13只为青春期前（<8个月）个体，所有个体均在繁殖季节（6月至8月）期间及之外（12月至2月）进行评估。在两个季节中，对所有动物的血清睾酮浓度、睾丸体积和颈围进行了分析。繁殖季节的特征是激素浓度显著升高、颈围和睾丸体积增加，成年鹿和繁殖季节之外的青春期前个体之间存在显著差异。在所有分析变量之间均观察到正相关：平均睾丸体积与颈围（r = 0.92，p < 0.0001）、睾丸体积与睾酮浓度（r = 0.79，p < 0.0001）以及颈围与睾酮浓度之间（r = 0.67，p < 0.0001）。鉴于所发现的结果，结论是即使在热带气候条件下，黇鹿的繁殖季节性也很明确，并且可能与光周期有关。
