Section of Reproduction, Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa.
Gen Comp Endocrinol. 2012 Sep 1;178(2):272-81. doi: 10.1016/j.ygcen.2012.05.008. Epub 2012 Jun 5.
Characterization of reproductive seasonality in the African wild dog (Lycaon pictus) could assist reintroduction programs. Male wild dogs (n=14) were assessed quarterly (January, mid-summer; April, late summer; August, late winter; November, early summer) for serum testosterone, body weight, testicular and prostatic volume, preputial gland measurement, and ejaculate characteristics. Bi-monthly fecal samples were collected from male (n=11) and female (n=4) wild dogs for analysis of fecal androgens and progestagens. Fecal androgens were higher in early summer (246.4 ± 14.5 ng/g) than in early winter (218.6 ± 13.4 ng/g). Serum testosterone was higher in mid-summer (1.4 ± 0.3 ng/ml) than in late winter (0.7 ± 0.1 ng/ml). Number of spermatozoa per ejaculate was greatest in late summer (301.4 ± 39.3 × 10(6)). Other semen parameters peaked in mid-summer (pH: 7.4; progressive motility: 85.0 ± 0.1%; live spermatozoa: 81.0 ± 16%; normal morphology: 71.5 ± 8.2%). Total testicular and prostatic volume were greater during summer (testicular: 36.7 ± 4.2 cm(3); prostatic: 12.0 ± 1.9 cm(3)) than winter (testicular: 25.2 ± 1.9 cm(3); prostatic: 5.8 ± 0.8 cm(3)). Preputial pendulance also was greater in summer (7.1 ± 0.5 cm; n=9) than winter (5.9 ± 0.2 cm). Baseline fecal progestagen metabolites were 6.2 ± 2.5 μg/g and peak fecal progestagen metabolites were 14.7 ± 2.8 μg/g. Copulations resulting in pregnancies (n=2) occurred in late summer and gestation was 71 days. Female wild dogs were seasonally monoestrous with mating in summer and winter. In conclusion, wild dogs are reproductively seasonal with improvement in male reproductive variables during summer and a bi-phasic seasonal pattern to female receptivity.
描述非洲野犬（Lycaon pictus）的繁殖季节性有助于重新引入计划。对 14 只雄性野犬（n=14）进行了季度评估（1 月，仲夏；4 月，夏末；8 月，冬末；11 月，初夏），评估指标包括血清睾酮、体重、睾丸和前列腺体积、包皮腺测量和精液特征。每月收集 11 只雄性（n=11）和 4 只雌性（n=4）野犬的粪便样本，以分析粪便中的雄激素和孕激素。粪便中的雄激素在初夏（246.4 ± 14.5 ng/g）时高于初冬（218.6 ± 13.4 ng/g）。血清睾酮在仲夏（1.4 ± 0.3 ng/ml）时高于冬末（0.7 ± 0.1 ng/ml）。每次射精中的精子数在夏末（301.4 ± 39.3×10(6)）时最高。其他精液参数在仲夏时达到高峰（pH：7.4；前向运动精子：85.0 ± 0.1%；活精子：81.0 ± 16%；正常形态：71.5 ± 8.2%）。夏季（睾丸：36.7 ± 4.2 cm(3)；前列腺：12.0 ± 1.9 cm(3)）时总睾丸和前列腺体积大于冬季（睾丸：25.2 ± 1.9 cm(3)；前列腺：5.8 ± 0.8 cm(3)）。夏季的包皮腺摆动度也较大（7.1 ± 0.5 cm；n=9），而冬季较小（5.9 ± 0.2 cm）。基础粪便孕激素代谢物为 6.2 ± 2.5 μg/g，峰值粪便孕激素代谢物为 14.7 ± 2.8 μg/g。导致怀孕的交配（n=2）发生在夏末，妊娠期为 71 天。雌性野犬季节性单发情，夏季和冬季交配。总之，非洲野犬具有季节性繁殖能力，夏季雄性繁殖变量得到改善，雌性接受度呈双相季节性模式。
