title: Altered concentrate to forage ratio in cows ration enhanced bioproduction of specific size subpopulation of milk fat globules.
abstract: The mechanism underlying the shift in milk-fat-globule (MFG) mean diameter upon changing the concentrate-to-forage ratio in dairy cow rations was investigated. Cows were fed high-concentrate low-forage (HCLF) or high-forage low-concentrate (LCHF) rations for 4 weeks. Mean diameter of MFG, determined in raw whole milk, was 0.4 μm larger in the LCHF-fed vs. HCLF-fed group. The main compositional differences between treatments were found in a specific MFG subgroup with the diameter of 3.3 μm (F1), with higher capric, lauric, myristic and lower oleic acid concentrations in HCLF vs. LCHF milk. Similarly, lipid concentration differences between treatments were only found in F1, with higher triglyceride and phosphatidylethanolamine, and lower sphingomyelin concentrations in LCHF vs. HCLF milk. The higher MFG mean diameter in whole raw LCHF milk might therefore be attributed to increased secretion of F1-group MFG, while fat content and composition in the other MFG size groups remains unchanged.
authors.affiliation: Animal Science Department, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Israel.
authors.forename: Ronit
authors.initials: R
authors.lastname: Mesilati-Stahy
authors.affiliation: Department of Ruminant Science, Institute of Animal Science, ARO, The Volcani Center, Bet-Dagan, Israel.
authors.forename: Uzi
authors.initials: U
authors.lastname: Moallem
authors.affiliation: Animal Science Department, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Israel.
authors.forename: Yogev
authors.initials: Y
authors.lastname: Magen
authors.affiliation: Animal Science Department, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Israel. Electronic address: argov.nurit@mail.huji.ac.il.
authors.forename: Nurit
authors.initials: N
authors.lastname: Argov-Argaman
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D002417:Cattle; D005227:Fatty Acids / Q000032:analysis; D005260:Female; D006017:Glycolipids / Q000032:analysis* / Q000096:biosynthesis; D006023:Glycoproteins / Q000032:analysis* / Q000096:biosynthesis; D006801:Humans; D066292:Lipid Droplets; D008892:Milk / Q000737:chemistry; D010316:Particle Size
chemical_list: D005227:Fatty Acids; D006017:Glycolipids; D006023:Glycoproteins; C110367:milk fat globule
keywords: Concentrate to forage ratio; Fatty acid; Membrane; Milk fat globule; Phosphatidylethanolamine; Phospholipid; Sphingomyelin