Pregnancy determination in uncaptured feral horses by means of fecal steroid conjugates.

The research focuses on developing a method of determining pregnancy in wild horses without capturing them, by analyzing certain metabolites present in their feces. This method is compared with the usual method of diagnosing pregnancy through urinary estrone conjugates.

Objective of the Study

• The study aimed to create an efficient, quick, and cost-effective method for detecting pregnancy in uncaptured, wild horses. To achieve this, the researchers developed a method focusing on the analysis of fecal steroid metabolites, which function as indicators of pregnancy.

Methodology

• The researchers collected paired urine and fecal samples from 40 sexually mature wild female horses in the months of August and October.
• The urine samples were directly derived from the ground and analyzed using enzymeimmunoassay (EIA) for E(1)C (estrone conjugates), a substance whose concentration in a horse’s urine increases during pregnancy.
• A similar EIA analysis was done with water extracts from the fecal samples. In addition to estrone conjugates, the researchers also searched for nonspecific progesterone metabolites (iPdG) which also act as pregnancy indicators.

Findings and Conclusion

• The researchers measured and compared specific fecal and urinary concentrations in mares that were confirmed to be pregnant and gave birth (foaling) and those who didn’t. They found that the concentrations of urinary E(1)C, fecal E(1)C, and fecal iPdG were significantly higher in mares that foaled.
• This difference confirmed that the levels of these substances markedly change when a wild horse is pregnant. Consequently, analyzing them in fecal samples can be a reliable non-invasive method to determine pregnancy in wild horses.