Effect of Tocopherol and Selenium on the Performance of Buserelin for Estrus Induction in Late Season Anestrus Mares (Equus Caballus)

Abstract

The aim of this study was to determine the effect of tocopherol and selenium on the performance of buserelin (GnRH analogue) for estrus induction in anestrus mares. A total of 18 seasonally anestrus mares were divided into three equal groups (n=6 in each) after ovarian scanning. Mares in group A (treatment group) were treated with tocopherol and selenium intramuscularly along with daily dose of buserelin. Mares which came into heat within ten-day buserelin protocol, further injections of buserelin for those mares were stopped. Mares in group B were treated with buserelin intramuscularly only for ten days. Mares which came into heat within ten-day buserelin protocol, further injections of buserelin were stopped. Blood/serum was collected from each experimental mare kept in different groups (A-C) at days 1, 11, 12, 13 and 14. Onset of estrus signs was 83.3, 33.3 and 0% in group A, B and C, respectively, that was significant (P<0.05) among groups. Follicular dynamics were 20.24±3.00, 14.59±2.24 and 10.35±0.63mm in groups A, B and C, respectively with significant (P˂0.05) difference. Change in serum E2 contents was significantly (P˂0.05) different among groups A, B and C whereas progesterone concentration showed non-significant difference among groups.