Confinement and pasture-based dairy herds differ in plasma lipid profiles.

Area of Science:

• Dairy cattle science
• Lipidomics
• Animal nutrition

Background:

• Dairy cow housing systems, intensive confinement (CONFINE) or pasture-based (PAST), influence diet composition, particularly forage and lipid profiles.
• Differences in dietary lipids may affect cow health, reproduction, and aging, but the impact on blood lipidomics is unknown.

Purpose of the Study:

• To investigate differences in blood lipids and metabolites between dairy cows in CONFINE and PAST housing systems during the dry period and at peak milk.
• To identify specific lipids associated with housing systems.

Main Methods:

• Cross-sectional, multisite study analyzing blood samples from 303 PAST and 398 CONFINE dry cows, and 350 PAST and 431 CONFINE peak-milk cows.
• Targeted liquid chromatography-mass spectrometry (LC-MS) evaluated 185 lipid species and 11 metabolites.
• Variable stabilization using penalized models and bootstrapping identified housing system-associated lipids.

Main Results:

• Dry CONFINE cows showed decreased globulin, urea, and n-3 fatty acid-associated glycerophospholipids (e.g., PC(36:5), PE(38:5)).
• Peak-milk CONFINE cows exhibited increased n-6 fatty acid-associated glycerophospholipids (e.g., PI(38:3), PC(34:2)) and decreased n-3 fatty acid-associated PC(34:3).
• Specific lipids were strongly associated with housing systems, with patterns differing between dry and peak-milk stages.

Conclusions:

• Dairy cow housing systems significantly alter blood lipid profiles, with CONFINE systems associated with reduced n-3 and increased n-6 fatty acids.
• These lipid alterations may indicate different risk profiles for reproduction, health, and aging in cows housed in CONFINE systems.
• Findings highlight the importance of housing and diet on bovine lipidomics and overall health.