Evaluation of clinical and luteolytic effects of a novel prostaglandin analogue in normal and problem mares.

The study examines the introduction of Alfaprostol, a new variant of the Prostaglandin F2 alpha hormone, in mares exhibiting different reproductive behaviors and conditions. It demonstrates the drug’s effective role as a luteolytic agent, inducing successful ovulation, conception, and birth rates without any observable adverse effects.

Objective and Methodology

• The purpose of this research was to evaluate the luteolytic and clinical effects of Alfaprostol (K 11941), a novel prostaglandin F2 alpha analogue that was tested on mares in differing stages of their reproductive cycle.
• A total of 95 equine subjects were part of this experiment: 24 mares in dioestrous (not fertile) stage, 40 mares in anoestrous (out of breeding season) stage, and 31 postpartum (following childbirth) mares.
• This study utilized intramuscular administration of either 2 or 3 mg of Alfaprostol. Blood samples were taken from the mares to measure plasma progesterone levels, informing researchers of the drug’s luteolytic effects.
• For comparative analysis, 236 similar mares were observed for rates of pregnancy, early embryonic loss, and foaling.

Findings

• The results showed that Alfaprostol was effective as a luteolytic agent, triggering oestrus (period of fertility), follicular development (growth and maturation of egg cells), and maintaining normal conception rates of 72.6% and foaling rates of 65.3%.
• No side effects were reported during the experiment, suggesting that Alfaprostol is a safe agent for inducing fertility in mares.
• Starting treatments early in the breeding season (October) when only 35% of the anoestrous mares exhibited elevated progesterone levels, resulted in 80% of treated mares entering oestrus and ovulating. This subsequently led to normal fertility, underscoring the potency of Alfaprostol.

Implications

• This study presents Alfaprostol as a promising tool in equine reproductive management. Its luteolytic properties and ability to induce productive estrus in mares could be utilized in breeding programs to increase fertility rates and successful births.
• Further research can explore the long-term impacts and effectiveness of Alfaprostol along with its potential applications in other livestock or animals.