Open AccessEffect of seasonal environmental changes on selected reproductive parameters in mares
Author(s) -
Zuzana Vilhanová,
František Novotný,
I. Valocký,
V. Hura,
Petra Horňáková,
M. Karamanová
Publication year - 2021
Publication title -
bulgarian journal of veterinary medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.211
H-Index - 10
eISSN - 1311-1477
pISSN - 1313-3543
DOI - 10.15547/bjvm.2019-0083
Subject(s) - estrous cycle , zoology , jugular vein , medicine , seasonal breeder , veterinary medicine , biology , ecology
The aim of this study was to monitor and evaluate the seasonal changes on selected reproductive parameters in mares. Ninety-six mares of different breeds, aged 3 to 23 years were evaluated during the breeding season 2015–2018 at the Equine clinic at University of Veterinary Medicine and Pharmacology in Košice, Slovakia (48°42´N, 21°15´E). The beginning of the estrus was determined by history or observation, mares were examined every 6 hours, blood for progesterone analysis was taken from the jugular vein. Correlation analyses were performed using both the Pearson and the Spearman correlation coefficient. Statistical analysis was performed using the functions of Microsoft Excel and GraphPad Prism. The day length (r = -0.708, P<0.0001) and the average ambient temperature (r = -0.754, P<0.0001) had a statistically significant effect on the duration of estrus. The shortest estrus was recorded in July with day length of 15 hours 40 minutes at an average temperature of 21.4 ± 0.52 °C, with duration 4.67 ± 0.58 days. The longest estrus was recorded in April with day length of 11 hours 48 minutes at average temperature of 6.9 °C. The environmental factors did not affect the size of the preovulatory follicles, the concentration of progesterone, the internal changes of uterus and the external manifestations of estrus.