Nycterohemeral variations of concentration of serum folates in dairy cows

Abstract

Nycterohemeral variations of serum folates were observed under two different management practices in 11 dairy cows. Serum folates were lower (P = 0.0018) during the nonlactating period (9.68 ± 0.65 ng mL −1 ) than during the lactating period (13.29 ± 0.65 ng mL −1 ). During the nonlactating period, nycterohemeral variations of serum folates could not be distinguished from experimental error. During the lactating period, expected serum folates did not vary by more than 1 ng mL −1 around their mean. Key words: Serum folates, nycterohemeral variations, lactating cows, nonlactating cows