Degrees of Antioxidant Protection: A 2-Year Study of the Bioactive Properties of Organic Milk in Poland.

The aim of this study was to determine the nutritional value of organic milk in Poland, investigate the influence of diet on antioxidant capacity and degree of antioxidant protection (DAP), and to examine the effect of season on the bioactive properties of milk from organic farms. From 2014 to 2015, 820 milk samples were collected from 6 organic farms during indoor feeding season (IDS) and pasture feeding season (PS). Pasture feeding season + corn grain (PSCG) cows' daily ration during pasture feeding season was enriched with 4 kg a day of corn to improve dietary energy balance. Milk obtained during PS was found to have a higher fat content, slight but significantly lower protein content compared with milk from IDS. The study showed that the content of monounsaturated fatty acids (MUFA) in milk fat was strongly linked to the concentration of polyunsaturated fatty acids (PUFA) and, to a lesser extent, on the supply of MUFA. The IDS data (concentration of vitamin E, A, and ß-carotene) showed the lowest values compared with the PS and PSCG groups. Total antioxidant status (TAS) and DAP showed an increasing trend in organic milk. PSCG was associated with highest level of DAP (9% higher than PS and 79% higher than IDS) and TAS (37% higher than PS and 79% higher than IDS). The results obtained show that supplementation of the basic ration with corn grain improved both TAS and DAP. The higher DAP and TAS value is responsible for product stability, considering the risk factor related to levels of cholesterol-oxide intake in humans.

Relationships between physiological indicators in blood, and their yield, as well as chemical composition of milk obtained from organic dairy cows.

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 ß-hydroxybutyric acid and the daily milk yield of lactating cows. ß-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). CONCLUSION: 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.