Carranza Juan, Yoong Washington A, Mateos Concha, Caño Vergara Belén, Gómez Chian L, Macías Verónica
Facultad de Medicina Veterinaria y Zootecnia, Universidad Agraria del Ecuador, Guayaquil, Ecuador.
Ungulate Research Unit, Cátedra de Recursos Cinegéticos y Piscícolas (CRCP), Universidad de Córdoba, Córdoba, Spain.
Anim Sci J. 2017 Dec;88(12):2063-2070. doi: 10.1111/asj.12818. Epub 2017 Jul 27.
Horse reproduction tends to be seasonal. The main adjusting factor in their original temperate ranges is photoperiod variation, although it is absent in equatorial areas where horses were introduced by European colonizers. Hence, dates of reproduction in these areas may be influenced by factors affecting mares' conditions and the success of foaling. Here we study reproductive timing in Creole horses in Ecuador reared in an extensive production system. We found that foaling peaked in August. Mares' conditions showed one peak in June-July, before the start of the breeding season, and another in December, and it was highly variable along the year. Mares' conditions increased after a period of vegetation growth and thus appeared negatively associated with the increment of grass greenness (normalized difference vegetation index data). Seasonal flooding of some pasturelands during March and April appeared to seriously impair mares' conditions and probably influenced the timing of foaling toward the dry season. Our results evidenced that horse breeding in these equatorial areas tended to be seasonal and point to some key factors that influence phenology by affecting body condition of mares, which may have implications for horse biology and management.
马的繁殖往往具有季节性。在其原本的温带地区，主要的调节因素是光周期变化，不过在欧洲殖民者引入马匹的赤道地区则不存在这种情况。因此，这些地区的繁殖日期可能会受到影响母马状况和产驹成功率的因素的影响。在此，我们研究了在粗放养殖系统中饲养的厄瓜多尔克里奥尔马的繁殖时间。我们发现产驹高峰期在8月。母马的状况在6月至7月（繁殖季节开始前）出现一个峰值，在12月出现另一个峰值，并且全年变化很大。经过一段时间的植被生长后，母马的状况有所改善，因此似乎与草的绿度增加（归一化植被指数数据）呈负相关。3月和4月期间一些牧场的季节性洪水似乎严重影响了母马的状况，并可能将产驹时间推迟到旱季。我们的结果表明，这些赤道地区的马匹繁殖往往是季节性的，并指出了一些通过影响母马身体状况来影响物候的关键因素，这可能对马的生物学和管理产生影响。
