title: Variation in nutritionally relevant components in retail Jersey and Guernsey whole milk.
abstract: This study investigates the quality of retail milk labelled as Jersey & Guernsey (JG) when compared with milk without breed specifications (NS) and repeatability of differences over seasons and years. 16 different brands of milk (4 Jersey & Guernsey, 12 non specified breed) were sampled over 2 years on 4 occasions. JG milk was associated with both favourable traits for human health, such as the higher total protein, total casein, α-casein, β-casein, κ-casein and α-tocopherol contents, and unfavourable traits, such as the higher concentrations of saturated fat, C12:0, C14:0 and lower concentrations of monounsaturated fatty acids. In summer, JG milk had a higher omega-3:omega-6 ratio than had NS milk. Also, the relative increase in omega-3 fatty acids and α-tocopherol, from winter to summer, was greater in JG milk. The latter characteristic could be of use in breeding schemes and farming systems producing niche dairy products. Seasonality had a more marked impact on the fatty acid composition of JG milk than had NS milk, while the opposite was found for protein composition. Potential implication for the findings in human health, producers, industry and consumers are considered.
authors.affiliation: Nafferton Ecological Farming Group, School of Agriculture Food and Rural Development, Newcastle University, Nafferton Farm, Stocksfield, Northumberland, NE43 7XD, UK. sokratis.stergiadis@ncl.ac.uk
authors.forename: S
authors.initials: S
authors.lastname: Stergiadis
authors.forename: C J
authors.initials: CJ
authors.lastname: Seal
authors.forename: C
authors.initials: C
authors.lastname: Leifert
authors.forename: M D
authors.initials: MD
authors.lastname: Eyre
authors.forename: M K
authors.initials: MK
authors.lastname: Larsen
authors.forename: G
authors.initials: G
authors.lastname: Butler
mesh_terms: D000818:Animals; D002417:Cattle / Q000145:classification / Q000378:metabolism*; D015525:Fatty Acids, Omega-3 / Q000032:analysis / Q000378:metabolism; D005260:Female; D006801:Humans; D008892:Milk / Q000737:chemistry* / Q000378:metabolism; D008894:Milk Proteins / Q000032:analysis / Q000378:metabolism; D009753:Nutritive Value; D011786:Quality Control; D012621:Seasons; D006113:United Kingdom
chemical_list: D015525:Fatty Acids, Omega-3; D008894:Milk Proteins