Obesity and gestation in Criollo mares: endocrine and metabolic profiles.

The research is an examination of how obesity influences the metabolic and hormonal changes in pregnant horses, specifically Criollo mares. It was found that markers such as leptin, glucose and insulin concentrations varied significantly between obese and non-obese mares during gestation.

Objective of the Research

In this study, the main aim was to determine how the body condition score (BCS), which is a measure of obesity, affects the endocrine and metabolic profiles of pregnant Criollo mares.

Methodology

• The researchers selected 41 Criollo mares which were divided by BCS into obese (7 to 9 BCS) or normal (5 to 7 BCS).
• During three different periods in the gestation (3.5-5 months, 8-9 months and the last month), blood samples were taken from the mares for testing.
• Using statistical models, the recorded BCS, gestation period, and their interaction were included as fixed effects.

Results

• The only difference in body condition score was found in the initial gestation period, with normal mares increasing their BCS in subsequent periods.
• Leptin levels were consistently higher in obese mares at all testing intervals. Similarly, glucose levels were higher in obese mares, but only during the first period.
• Insulin levels and the HOMA-IR index, a measure of insulin resistance, were also observed to be higher in the obese mares during the first and final periods of gestation.
• Lower levels of adiponectin, a protein hormone, were recorded in obese mares during the first period.
• Cholesterol levels increased throughout gestation and tended to be higher in the obese mares. Triglyceride levels remained unaffected by either the weight group or the gestation period.

Conclusion

This research observed the metabolic and hormonal adaptations in pregnant mares with varying levels of obesity. Multiple parameters were found to be dependent on their body fat reserves as reflected by molecules like leptin and adiponectin. For instance, insulin levels in obese mares were discovered to be higher at the gestation’s end compared to non-obese mares. A similar profile was seen in the HOMA-IR levels, indicating potential insulin resistance, yet specific cutoff values still need to be validated.