[Progesterone determination in milk]

Area of Science:

• Reproductive biology
• Endocrinology
• Veterinary science

Context:

• Assessing reproductive status in cattle is crucial for herd management.
• Progesterone monitoring is a key indicator of ovarian function and pregnancy.
• Understanding corpus luteum activity aids in optimizing breeding programs.

Purpose:

• To determine the reliability of serial milk progesterone measurements for detecting corpus luteum activity in dairy cows.
• To establish optimal sampling times for accurate progesterone analysis from milk.

Summary:

• Milk samples were collected hourly from ten cows over a ten-hour period to measure progesterone concentrations.
• Progesterone levels were correlated with strippings, providing evidence of corpus luteum function.
• Most samples reliably indicated an active corpus luteum, with potential exceptions in late-stage pre-milking samples.

Impact:

• Provides evidence for using serial milk progesterone measurements as a non-invasive method for reproductive monitoring in cows.
• Informs optimal sampling strategies to maximize the accuracy of reproductive status assessments.
• Contributes to improved reproductive efficiency and herd health management in cattle.