title: Discrimination of "grazing milk" using milk fatty acid profile in the grassland dairy area in Hokkaido.
abstract: Milk produced by the grazing system, referred to as "grazing milk" contains many components required for human health. The milk fatty acid (FA) profile is strongly associated with the diet on the farms. In the present study, based on the FA profile of farmer's bulk milk, we determined how to discriminate between milk produced on grazing and on a confinement system. A field survey was conducted four times (grazing and confinement season) in the Konsen (29 farms) and Okhotsk (25 farms) area in Hokkaido. Farmer's bulk milk samples and details of feeding management were collected and the FA profile of milk was measured. Milk produced during the grazing season contained less C16:0 and cis-9 C16:0, and more C18:0, cis-9 C18:1, trans-11 C18:1, cis-9,12 C18:2, cis-9,trans-11 C18:2 and cis-9,12,15 C18:3 than milk produced during the confinement season. Discrimination analysis using 16 FA revealed that almost all milk samples were discriminated correctly (confinement season: 90% correct and 10% borderline, grazing season: 88% correct, 9% borderline and 3% incorrect). For farmers that were categorized incorrectly and were considered borderline in the grazing season, the dependency on pasture was low compared with that for farmers correctly discriminated. Therefore, to claim "grazing milk", a high dependency on pasture is required for grazing dairy farmers.
authors.affiliation: Creative Research Institution, Hokkaido University, Sapporo, Japan.|Field Science Center for Northern Biosphere, Hokkaido University, Sapporo, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Mitani
authors.affiliation: Creative Research Institution, Hokkaido University, Sapporo, Japan.|Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan.
authors.forename: Kuniyuki
authors.initials: K
authors.lastname: Kobayashi
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Ueda
authors.affiliation: Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Kondo
mesh_terms: D000821:Animal Feed; D000818:Animals; D002417:Cattle; D020378:Confined Spaces; D003612:Dairying / Q000379:methods*; D005227:Fatty Acids / Q000032:analysis*; D005260:Female; D060434:Herbivory; D007564:Japan; D008892:Milk / Q000737:chemistry* / Q000145:classification*; D006109:Poaceae; D012621:Seasons
chemical_list: D005227:Fatty Acids
keywords: discrimination; fatty acid profile; grassland dairy area; grazing milk