Patterns of urinary oestrogen excretion in individual pregnant mares.

This research examines the changes in urinary oestrogen levels in pregnant Pony mares throughout their pregnancy, noting individual differences.

Purpose and Method of the Study

• The main goal of this study was to analyze the patterns of urinary oestrogen excretion in pregnant Pony mares.
• The researchers collected urine samples from four Pony mares every 24 hours, starting from the 3rd or 4th months of their pregnancy until they gave birth.
• The collected samples were processed using a process of separation on Celite columns, and the levels of oestrone and equilin, two types of oestrogens, were measured using Kober measurements.

Findings of the Study

• The study found individual differences among the mares in regards to the peak amounts of total oestrogens excreted, which ranged from 200 to 800 mg/day.
• It was observed that oestrone was the major constituent of the oestrogens, making up 80 to 95% of the total during the 6th to 7th months of pregnancy.
• While the level of equilin, another type of oestrogen, increased in the later stages of gestation, oestrone still remained the major product.

Patterns of Oestrogen Levels Throughout Pregnancy

• According to the research, the total oestrogen levels decreased rapidly from the peak and then more gradually towards the end of pregnancy.
• In the last three weeks of pregnancy, the decline in the ratio of oestrone to equilin reversed in all the studied mares.

Conclusions of the Study

• The ultimate conclusion is that urinary oestrogen levels in pregnant Pony mares show specific patterns and significant individual differences.
• This finding could potentially provide useful information for understanding hormonal changes during equine pregnancy and monitoring equine reproductive health.