miRNAS and target genes are regulated post-training in quarter horse athletes.

Overview

• This study examined how microRNAs (miRNAs) and their target genes, which influence metabolic functions, change after training in Quarter Horses, a popular and athletic horse breed in Brazil.
• The research also assessed changes in blood and clinical health markers to understand how exercise affects the physiological state of these horses.

Background and Purpose

• The Quarter Horse (QH) breed is significant in Brazilian equestrian sports, being the third largest registered horse population in the country.
• Despite their popularity and athletic importance, there is limited molecular-level research on their health and performance.
• The study focused on investigating changes in specific molecular markers known as microRNAs and their corresponding target genes involved in metabolic pathways related to exercise.
• Furthermore, the study aimed to evaluate hematological (blood) and clinical changes after exercise to provide a comprehensive view of physiological alterations in these horses.

Methodology

• Subjects: Ten Quarter Horses of both sexes, approximately 6 years old, weighing between 400 and 513 kg (average 442.3 kg).
• Conditions: Horses were kept under consistent management regarding housing, feeding, and training to minimize external variability.
• Exercise Protocol: Horses participated in a race involving obstacle deviation, simulating athletic exertion.
• Measurements: Clinical assessments, hematology tests, and molecular analysis of microRNAs and their target genes were performed before and after the exercise.

Key Findings

• Significant differences (p < 0.05) were observed in clinical, hematological, and molecular parameters post-exercise.
• These changes included increases related to oxygen transport, suggesting enhanced delivery of oxygen to tissues during and after exercise.
• Alterations in oxygen metabolism were noted, implying increased energy conversion efficiency necessary for physical activity.
• The post-training recovery phase involved activation of inflammatory responses, which is typically a part of the adaptation to aerobic exercise.
• The modulation of miRNAs and their target genes indicates molecular level regulation aligned with the physiological demands of exercise.

Conclusions and Implications

• The study highlights important bioindicators that can be used to monitor animal health and athletic performance in Quarter Horses, particularly those raised in the Amazon region.
• Understanding how miRNAs and gene expression change post-training helps in managing horses for optimal performance and recovery.
• The findings provide a foundation for developing molecular and physiological markers that trainers and veterinarians can use to assess training status and health.
• This research fills a gap in equine sports science by linking molecular biology with clinical and hematological parameters in athletic horses.