title: Relationships between physiological indicators in blood, and their yield, as well as chemical composition of milk obtained from organic dairy cows.
abstract: BACKGROUND
  The occurrence of metabolic overload in cows maintained in organic herds is very likely, because organic production promotes feeding with high roughage diets and discourages supplementation with concentrates supplementation. It has the potential to negatively affect milk quality. The aim of this study was to determine the influence of physiological indicators in blood, reflecting the energy metabolism and liver status of dairy cows kept in organic herds, on the content of bioactive components in milk and the influence of lactation stage and feeding season on changes in milk components.
  
  
  RESULTS
  A significant positive correlation was found between β-hydroxybutyric acid and the daily milk yield of lactating cows. β-Hydroxybutyric acid was negatively correlated with lactation phase and polyunsaturated fatty acids as well as saturated fatty acids content in milk. A significant negative correlation was observed between average daily milk yield and alanine aminotransferase concentration in blood. A low level of production in organic farms had a positive impact on the content of conjugated linoleic acid (20% increase), vitamin A (21% increase) and vitamin E (11% increase).
  
  
  CONCLUSIONS
  The study has shown significant correlations between metabolic profiles and milk yields, as well as milk composition. In addition, there is evidence that the intensity of the production system significantly influences the metabolic profile and chemical composition of cow's milk. It could even be concluded that the ecological system affects not only the quality of milk, but also the health of cows.
authors.affiliation: Department of Animal Science, Institute of Genetics and Animal Breeding, Polish Academy of Science, Jastrzębiec, Poland. t.sakowski@ighz.pl
authors.forename: Tomasz
authors.initials: T
authors.lastname: Sakowski
authors.forename: Beata
authors.initials: B
authors.lastname: Kuczyńska
authors.forename: Kamila
authors.initials: K
authors.lastname: Puppel
authors.forename: Ewa
authors.initials: E
authors.lastname: Metera
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Słoniewski
authors.forename: Jerzy
authors.initials: J
authors.lastname: Barszczewski
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D017849:Animals, Inbred Strains; D015415:Biomarkers / Q000097:blood; D002417:Cattle / Q000097:blood / Q000254:growth & development* / Q000502:physiology; D003612:Dairying / Q000379:methods*; D004734:Energy Metabolism; D005260:Female; D063427:Food Quality; D058870:Food, Organic / Q000032:analysis*; D007774:Lactation; D044243:Linoleic Acids, Conjugated / Q000032:analysis / Q000378:metabolism; D008099:Liver / Q000502:physiology; D008111:Liver Function Tests / Q000662:veterinary; D008892:Milk / Q000737:chemistry* / Q000378:metabolism; D011044:Poland; D012621:Seasons; D012820:Silage / Q000032:analysis; D014801:Vitamin A / Q000032:analysis / Q000378:metabolism; D014810:Vitamin E / Q000032:analysis / Q000378:metabolism
chemical_list: D015415:Biomarkers; D044243:Linoleic Acids, Conjugated; D014801:Vitamin A; D014810:Vitamin E