Compositional and electrophoretic changes in buffalo milk-fat globule membrane proteins during lactation

Area of Science:

• Dairy Science
• Biochemistry
• Animal Science

Background:

• Milk-fat globule membrane proteins (FGMP) play crucial roles in milk processing and nutrition.
• Understanding compositional changes in FGMP during lactation is vital for optimizing dairy production.

Purpose of the Study:

• To investigate the changes in the composition and protein profile of milk-fat globule membrane proteins (FGMP) in Murrah buffaloes throughout different lactation stages.
• To analyze variations in chemical composition and protein expression from colostrum to late lactation.

Main Methods:

• Chemical analyses were performed to assess levels of sialic acid, hexose, hexosamine, Nitrogen (N), and Phosphorus (P).
• Sodium dodecyl sulphate polyacrylamide-gel electrophoresis (SDS-PAGE) was used to determine the major proteins in FGMP.
• Isoelectric focusing (IEF) was employed to analyze the complexity and heterogeneity of FGMP.

Main Results:

• Significant changes in sialic acid, hexose, hexosamine, N, and P levels were observed in FGMP across lactation stages.
• SDS-PAGE revealed 8 major proteins in FGMP on parturition day, decreasing to 6 in middle and late lactation.
• Isoelectric focusing showed an increase in protein complexity, with 8-9 proteins in colostrum, 9-13 in middle lactation, and 13-16 in late lactation.

Conclusions:

• The composition and protein profile of milk-fat globule membrane proteins (FGMP) in Murrah buffaloes undergo significant alterations during lactation.
• These changes, particularly in protein number and heterogeneity, suggest dynamic functional adaptations throughout the lactation cycle.