Comparative proteomic analysis of the changes in mare milk associated with different lactation stages and management systems.

The research article investigates the different proteins present in mare milk at various stages of lactation and under different management systems. The study aims to enhance our understanding of the nutritional potency of mare milk and its potential health benefits.

Objective and Methodology

• The objective of the research is to conduct a comprehensive study of the proteomic (protein) composition of mare milk, focusing particularly on caseins and whey proteins, and understanding how different lactation stages and management systems affect the protein content.
• To achieve this aim, milk samples were drawn from Basque Mountain Horse breed mares located at three different farms and at three different lactation stages.
• The analysis involves an in-gel and in-solution digestion method and the use of nLC-MS/MS, a liquid chromatography technique coupled with tandem mass spectrometry, to identify and characterise the proteins present.

Findings

• The researcher identified 469 distinct proteins in total across all samples.
• The content of alpha-1 antitrypsin, a protein that protects the tissues from enzymes of inflammatory cells, was noticeably higher in samples from pasture-based mares compared to others. Thus, the management system appeared to have a significant impact on the presence of this particular protein.
• The lactation stage also influenced the presence of several proteins, including beta-lactoglobulin II, a whey protein, immunoglobulin-like domain-containing protein, interferon alpha-inducible protein 27, lactotransferrin, a protein with antimicrobial activity, polypeptide N-acetylgalactosaminyltransferase, an enzyme involved in the metabolism of proteins and lipids, and transforming acidic coiled-coil containing protein 2.

Conclusion

• The study offered a holistic analysis of the proteome (the entire set of proteins) present in mare milk. Moreover, it demonstrated that the protein composition notably differs based on the stage of lactation and the management method.
• As a broader outcome, these findings provide new insights into the nutritional profile of mare milk. In addition to its existing attributed health benefits, understanding its protein composition could lead to potential health applications and spur further research into mare milk-based health products.