Oleic acid as a biomarker for early diagnosis of elevated blood levels of non-esterified fatty acids and β-hydroxybutyric acid in the early stages of lactation in high-yielding Polish Holstein cows

Inappropriate doses and quality of dietary nutrients cause problems in providing the protein and energy balance in a feed ration. Especially, energy value of the feed ration poses many problems to dairy cattle breeders and particularly in the perinatal period, which results in increased incidence of metabolic disorders. These disorders are today one of the most frequent causes of culling of dairy cows, as they underlie most of the disease entities. The aim of this experiment was, therefore, to verify the hypothesis that oleic acid (OA) can be used as a biomarker for early diagnosis of elevated blood levels of non-esterified fatty acids (NEFAs) and beta-hydroxybutyric acid (BHBA) in the early stages of lactation in high-yielding Polish Holstein (PHF) cows. The highest blood levels of NEFAs and BHBA of 1.573 and 1.116 mmolL(-1), respectively, was associated with the highest content of OA in milk fat. High concentrations of both NEFAs and BHBA, indicating explicitly the occurrence of the metabolic disease in cows, occur when the content of OA in milk exceeds 24g 100g(-1) of fat. Oleic acid may be used as a biomarker for the early diagnosis of elevated blood levels of NEFAs and BHBA in the early stages of lactation in high-yielding PHF cows.