SOME RELEVANT FACTORS REGARDING EMBRYONIC RECOVERY RATES IN A PROGRAM OF EMBRYO TRANSFER IN BRAZILIAN JUMPING HORSE MARES

Abstract

The aim of the present research was to evaluate some relevant aspects, potentially able to interfere in the fertility rates of Brazilian horse jumping mares from a Trade Center of Embryo Transfer. Results from a total of 699 embryos samples from 120 donors animals were considered and analysed, covering the reproductive seasons of the years 2003/2004, 2004/2005; 2005/2006 and 2006/2007. Among the 120 embryo donors, there were both healthy and problem mares, in regard to their reproducing ability. It has been observed significative differences in the artificial inseminations (IAS) in regard to the used method for semen preservation, having an expressive use of frozen semen in the equine embryo transfers (TES). On the other hand, no differences were found in the percentage collected embryo of within or out of the reproductive station, in regard to the collect carried out in different months of the respective year. Concerning to the rates of embryonary recovery and age a difference (p<0.01) has been observed in the collects carried out at the days 7, 8 and 9 after the ovulation, when compared with the recovery rates from the days 6 and 10. Data relative to the embryonary recovery in relation to the mares type of ovulation (single or multiple) it has been found that a larger number of embryos (p<0,01) was observed in mares with multiple ovulation in comparison to those with single ovulation.