Strip-dried whole milk sampling technique for progesterone detection in cows by ELISA

Area of Science:

• Veterinary Science
• Reproductive Biology
• Analytical Chemistry

Background:

• Accurate monitoring of progesterone levels is crucial for assessing cow reproductive status.
• Traditional milk sampling methods can present challenges in collection, transportation, and storage.
• Developing stable, easy-to-use sampling formats is essential for widespread field application.

Purpose of the Study:

• To introduce and optimize a novel strip-dried whole cow's milk sampling format for progesterone Enzyme-Linked Immunosorbent Assay (ELISA).
• To investigate and resolve methodological issues associated with this new sampling technique.
• To assess the storage stability of progesterone in strip-dried milk samples under various temperature conditions.

Main Methods:

• Optimization of strip dimensions, membrane cut-off shape, and sample application for strip-dried milk.
• Analysis of progesterone distribution uniformity along the dried milk strips.
• Evaluation of progesterone stability in strip-dried samples stored at 4°C, ambient temperature, 37°C, and 60°C.

Main Results:

• Progesterone distribution was largely uniform along the strip, with a slight concentration increase in the initial 0.5 × 0.5cm segment.
• Storage stability was generally good, though elevated temperatures showed increased detected progesterone, particularly in samples from non-pregnant cows.
• The strip-dried format proved suitable for sample collection, transport, storage, and subsequent ELISA analysis.

Conclusions:

• Strip-dried whole cow's milk offers a viable and stable format for progesterone analysis.
• This method simplifies progesterone measurement, aiding in the assessment of cow reproductive status.
• The optimized protocol enhances the reliability and practicality of field-based reproductive health monitoring in cattle.