Plasma progesterone levels in progesterone treated cows.

Area of Science:

• Veterinary Medicine
• Endocrinology
• Animal Reproduction

Background:

• Hormonal synchronization of oestrous cycles is crucial for efficient cattle breeding programs.
• Accurate measurement of progesterone levels is essential for monitoring reproductive status.

Purpose of the Study:

• To describe a radioimmunoassay technique for plasma progesterone measurement in cattle.
• To evaluate the effectiveness of progesterone administration for oestrous cycle synchronization.

Main Methods:

• Developed and applied a radioimmunoassay for plasma progesterone.
• Administered progesterone intramuscularly to synchronize oestrous cycles in cows and heifers.
• Collected blood samples daily or two-daily for progesterone level analysis.

Main Results:

• The radioimmunoassay technique provided reliable progesterone measurements.
• Progesterone administration maintained plasma levels consistent with the luteal phase.
• Post-treatment progesterone decline was slower than anticipated, potentially due to residual corpus luteum activity.

Conclusions:

• The described radioimmunoassay is suitable for assessing plasma progesterone in cattle.
• Progesterone synchronization protocols require careful consideration of post-treatment hormone clearance dynamics.