Plasma concentrations of 15-ketodihydro-PGF(2alpha), cortisol and progesterone during manual twin reduction in thoroughbred mares.

The research paper examines the hormonal changes that occurred in mares during the manual twin reduction process, comparing two different techniques of crushing one embryo within 19 days of the last mating. It was observed that these processes had no significant effect on plasma concentrations of 15-ketodihydro-PGF(2alpha), cortisol, or progesterone, though a slight increase in cortisol levels was noted 30 minutes following the fixed technique of crushing, which may indicate some level of stress in the mare.

Objective of the Study

• The research aimed to identify the hormonal changes in mares during manual twin reduction via mobile and fixed techniques of one embryo crushing performed within 19 days following the last mating.

Methodology

• The randomized study was conducted on ten twinning mares, with blood samples collected before and after the procedure at specific intervals (20 min prior to, 90 min, 24 h, and 72 h after performing the procedure).
• The examined hormones were 15-ketodihydro-PGF(2alpha), cortisol, and progesterone.

Exclusions

• One mare, where the unwanted crushing of both embryos occurred during an attempt to manually separate the twins, was not considered in the evaluation of induced hormonal changes due to the crushing procedure.

Findings

• No significant changes in hormonal concentrations were observed after the crushing of one embryo, regardless of whether the mobile or fixed method was used.
• However, a higher cortisol level was reported 30 minutes after using the fixed technique compared to the mobile one, suggesting the possibility of a slight stress influence on the mare from the fixed technique.
• The conclusion of the study is that crushing performed within 19 days of gestation does not noticeably affect the plasma concentrations of the studied hormones (15-ketodihydro-PGF(2alpha), cortisol, or progesterone).

Implications

• The results of this study could serve as a guide for practitioners in selecting the appropriate twin reduction method in mares, given the potential for a small increase in stress following the fixed crushing technique.