The red brocket deer is the largest species in the genus Mazama and one of the most abundant and widely distributed cervid in the Neotropics. Yet it has been classified as data deficient by the IUCN, and the limited knowledge on its reproductive biology indicates that red brocket bucks do not possess an annual antler cycle and are capable of breeding during antler casting and growth. Here, in parallel to antler cycle, we investigated seasonal changes in morphometric (body weight, neck and chest girth, and testicular volume), endocrine [plasma testosterone and fecal androgen metabolites (FAM) levels] and seminal (total sperm count and sperm motility index) parameters from captive adult red brocket bucks collected on a quarterly basis over a 1-year period. Two out of six males kept hard antlers year-round, three cast antlers from winter to spring, and one carried velvet antlers for longer than 6 months. No clear seasonal patterns of variation in gross morphometry, seminal traits, and hormonal levels were found, and mean values of all collected parameters did not show differences among seasons. Body weight was positively correlated with most morphometric measurements and seminal parameters, while chest girth was positively correlated with neck girth, testicular volume, and total sperm count. Neither androgen levels (both plasma testosterone and FAM) nor hard antler phase correlated with seminal characteristics. Our findings support that red brocket bucks not only exhibit aseasonal and asynchronous antler cycles, but also maintain their secondary sexual characteristics and semen quality unchanged over the year. This apparent lack of photoperiodic stimuli for controlling reproduction along with an absence of relationship between seminal parameters and antler status might make red brockets unique in terms of reproductive biology among deer species.

中文翻译：

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红bro鹿的异步繁殖：雄性生殖特性，精液参数，雄激素水平和鹿角周期的季节性变化

红色短角鹿属是属中最大的品种马札马是新热带地区数量最多，分布最广的鹿角之一。但是，IUCN已将其归类为缺乏数据，并且对其生殖生物学的有限了解表明，红bro没有一年生的鹿角周期，并且能够在鹿角施肥和生长期间繁殖。在这里，与鹿角周期平行，我们调查了形态变化（体重，脖子和胸部的周长和睾丸体积），内分泌[血浆睾丸激素和粪便雄激素代谢物（FAM）水平]和精液（总精子数和精子活力）的季节性变化。指数）的参数是在一年的时间内每季度从成年圈养的成年红red雄鹿身上收集的。六分之一的雄性终年保持坚硬的鹿角，三只从冬天到春季保持成年的鹿角，一头的鹿茸超过6个月。没有发现明显的总体形态，精子特征和荷尔蒙水平变化的季节性模式，所有收集参数的平均值均未显示出季节之间的差异。体重与大多数形态测量和精液参数呈正相关，而胸围与颈围，睾丸体积和精子总数呈正相关。雄激素水平（血浆睾丸激素和FAM）或硬鹿角期均与精液特征无关。我们的研究结果表明，红bro雄鹿不仅表现出季节性和异步的鹿角周期，而且在一年中仍保持其次要性特征和精液质量不变。