Short communication: A decrease in diameter of milk fat globules accompanies milk fat depression induced by...

Area of Science:

• Dairy Science
• Animal Nutrition
• Lipid Metabolism

Background:

• Milk fat globules (MFG) are crucial for milk fat secretion.
• Milk fat depression is a complex phenomenon affecting MFG synthesis.
• Conjugated linoleic acid (CLA) is known to impact milk composition.

Purpose of the Study:

• To investigate the effect of CLA on MFG size and distribution during milk fat depression.
• To understand how CLA influences the physical characteristics of milk fat.

Main Methods:

• Twelve mid-lactation Holstein cows were assigned to a control or CLA-supplemented diet for 6 days.
• Milk fat content, average MFG diameter, and particle size distribution were analyzed.
• A Mastersizer 3000 laser particle size analyzer was used for MFG measurements.

Main Results:

• CLA supplementation significantly decreased milk fat content (3.46% to 2.52%).
• The surface area-related mean diameter of MFG was reduced in cows fed CLA (3.02 μm vs. 3.45 μm).
• CLA increased the percentage of small MFG while decreasing large MFG.

Conclusions:

• CLA induces milk fat depression in dairy cows.
• This depression is associated with a reduction in the average diameter of milk fat globules.
• CLA alters MFG size distribution, favoring smaller globules.