The effect of bovine diets and stages of lactation on vitamin K content in butter and Cheddar cheese

This study investigated the vitamin K content in butter and Cheddar cheese produced from the milk of cows fed three different diets: pasture-fed (GRS), total mixed ration (TMR), and partial mixed ration (PMR), across early, mid, and late stages of lactation. Vitamin K1 and menaquinones (MK)-4, 7, and 9 were quantified using high-performance liquid chromatography (HPLC) with a fluorescence detector. Results showed that butter and Cheddar cheese made from higher ratio of pasture-fed milk exhibited significantly higher K1 levels (P < 0.05). GRS butter demonstrated the highest MK-4 content (P < 0.05), whereas TMR Cheddar cheese showed the highest MK-4 levels (P < 0.05), followed by GRS and PMR cheeses. Mid-lactation butter contained higher concentrations of K1 and MK-4 compared to early- or late-lactation stages (P < 0.05). Late-lactation Cheddar cheese contained significantly higher K1, MK-4, and MK-9 than early or mid-lactation cheeses (P < 0.05). These findings suggest that bovine diets with a higher pasture-fed ratio can enhance the vitamin K content in dairy products.