[Plasma progesterone in mares showing oestrus during early pregnancy (author’s transl)].

This study investigates the relationship between plasma progesterone levels and the display of oestrus in mares during early pregnancy. The researchers wanted to determine whether measuring progesterone could assist in diagnosing oestrus.

Research Methods and Participants

• The research study involved 64 mares who were studied at two points – 3 weeks and 6 weeks after mating.
• Twenty-two of these mares had their progesterone levels measured 3 weeks after mating with an intention to study its potential influence on the oestrus diagnosis.

Findings & Clinical observations

• The researchers found that none of the pregnant mares had plasma progesterone levels below 2 ng/ml.
• Pregnant mares that did not display signs of oestrus were shown to have higher levels of plasma progesterone in comparison to pregnant mares who showed signs of oestrus 3 weeks after mating.
• This suggests a potential link between plasma progesterone levels and the display of oestrus in mares during early pregnancy.

Comparison and Discussion

• The researchers also compared the clinical findings in pregnant and non-pregnant mares 3 weeks after mating.
• They further discussed the occurrence of oestrus in pregnant mares, providing a comprehensive understanding of this biological phenomenon and its potential links to progesterone levels.

Significance of the Study

• This study could help in accurately determining the oestrus stage in mares and understanding how hormonal changes influence this stage, thereby assisting in breeding decisions and management.
• Moreover, if plasma progesterone could be a reliable indicator of oestrus, vet doctors could use it as a non-invasive method of early pregnancy diagnosis in mares.