Fescue toxicosis.

This research delves into the effects of fescue toxicosis, specifically how the toxins in tall fescue, primarily ergovaline, affect mares during the late stages of pregnancy.

Understanding Fescue Toxicosis

• Fescue toxicosis is the result of animals consuming tall fescue grass infected by the endophyte fungus, N. coenophialum. This symbiotic relationship provides nourishment for the fungus from the plant, and in return, the plant receives toxins it uses for defense.
• The primary toxins causing harm to animals are ergopeptine alkaloids, particularly ergovaline.
• Ergovaline functions as a dopamine D2 agonist (mimics the action of dopamine), leading to significant hormonal changes in the body.

Impact on Pregnant Mares

• The toxins found in tall fescue significantly impact pregnant mares, especially during the last month of gestation.
• The hormonal alterations that occur as an effect of the dopamine D2 agonist have severe consequences for gestation and birth in mares.

Effects and Symptoms of Fescue Toxicosis

• The common symptoms of fescue toxicosis are extended gestation (prolonged pregnancy beyond the normal period), difficulty in delivering (dystocia), problems with the expulsion of the placenta following birth (retained placentas), (lack of milk production agalactia).
• The foals born to affected mares are typically underdeveloped (dysmature), often stillborn, or exhibit weakness at birth.

Conclusion

• The research highlights the negative effects of fescue toxicosis on pregnant mares and their offspring, induced by endophyte-infected tall fescue. Greater awareness and understanding of these effects would aid in the development of prevention strategies and treatments to mitigate these harmful impacts.