Anotace:
β-carotene has many important functions in the body: as a precursor of vitamin A, it works as antioxidant and affects the fertility of cows. This paper presents the results of measurements of the content of β-carotene in the blood serum of cows from different farms in Slovenia. Blood samples of cows (n = 604) from 176 farms with impaired fertility were analysed for β-carotene content using Yudkin's photometric method. The descriptive statistics and the proportion of samples that deviated from the reference values were calculated. Influence of month of sampling and farm on β-carotene level was studied as well. The median value of β-carotene in the investigated samples was 5.02 mg/L (minimum 0.63 mg/L, maximum 16.10 mg/L) and was within the reference range. In 32.8% of cow samples, the content of β-carotene was below the reference value (4.0 mg/L). According to the results, we believe that this is not a negligible problem in Slovenian farms, and that it is advisable to control β-carotene status in cows, especially in herds where fertility is impaired and in farms where the composition of the diet indicates the possibility of β-carotene deficiency.