Differences in Milk Proteomic Profiles between Estrous and Non-Estrous Dairy Cows

Area of Science:

• Animal Science
• Biochemistry
• Reproductive Biology

Background:

• Accurate estrus identification is vital for dairy cow reproductive efficiency.
• Current methods like visual observation are unreliable, necessitating novel biomarker discovery.
• Proteomics offers a promising approach for identifying non-invasive biomarkers in milk.

Purpose of the Study:

• To identify potential protein biomarkers in milk for reliable estrus detection in dairy cows.
• To utilize proteomics to compare milk protein profiles between estrus and non-estrus states.

Main Methods:

• Milk samples were collected from pregnant dairy cows on estrus (day 0) and non-estrus (day -3) days.
• Tandem mass tags (TMT) proteomics approach was employed for protein analysis.
• Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed.

Main Results:

• A total of 89 differentially expressed proteins were identified between estrus and non-estrus milk.
• 33 proteins were upregulated, and 56 were downregulated in estrus milk.
• Key proteins involved in lipid metabolism, such as ACACA, APOB, and PLIN2, were identified and linked to estrus regulation.

Conclusions:

• Specific milk proteins, particularly those involved in lipid metabolism, show potential as biomarkers for estrus detection in dairy cows.
• Further validation in larger populations is required to confirm the utility of these proposed biomarkers.