The Functional Amino Acid l-Proline Enhances Lactation Performance by Activating the SNAT2-P4HA2-mTORC1 Axis

Area of Science:

• Animal Science
• Biochemistry
• Metabolomics

Background:

• Milk biosynthesis is complex and influenced by amino acid metabolism.
• Key regulatory amino acids and their mechanisms in milk production are not fully understood.

Purpose of the Study:

• To identify key amino acids regulating milk production in dairy cows.
• To elucidate the molecular mechanisms underlying amino acid regulation of milk synthesis.

Main Methods:

• Targeted metabolomics to identify differential serum metabolites.
• In vitro studies using bovine mammary epithelial cells.
• In vivo feeding trials with rumen-protected l-proline.

Main Results:

• L-proline (l-Pro) was identified as a key differential metabolite in high-yielding cows.
• In vitro, l-Pro promoted cell proliferation and milk fat/protein synthesis.
• In vivo, rumen-protected l-Pro increased milk yield and quality.

Conclusions:

• L-proline regulates milk synthesis via the SNAT2-P4HA2-mTORC1 signaling pathway.
• This pathway represents a novel mechanism for enhancing dairy cow production.
• L-proline supplementation is a potential strategy for improving dairy performance.