Daily rhythm and seasonal variation of serum pancreatic alpha amilase in Holstein bovine maintained under natural environmental condition in Southern Hemisphere

In this study the effect of daily rhythm, season, gender and productive status on serum pancreatic alpha amylase was evaluated in clinically healthy Holstein cattle from Southern Hemisphere. A total of 18 animals were enrolled in the study and equally di-vided in three groups according to their gender and lactation class: Group A (dairy cows at first lactation class); Group B (dairy cows at third lactation class); Group C (bulls). Groups A and B were in the same productive throughout the investigation (dry period in winter, early lactation in spring, mild lactation in summer, end lactation in autumn). From each animal blood sam-ples were collected every 3 hours over 24-hour period, every three months (winter, spring, summer, autumn) and on the serum obtained the concentration of serum alpha amylase has been assed. The application of two-way analysis of variance (ANOVA) showed a significant effect of season and group (gender and productive status) on alpha amylase. Cosinor rhythmometry showed a diurnal daily rhythmicity of alpha amylase in autumn, winter and spring in group A, in summer and autumn in group B and in all seasons in group C. This study suggests that seasonal and physiological conditions must be taken into consideration for the correct interpretation of serum chemistry in bovine in order to establish an accurate interpretation of laboratory data, crit-ical in diagnosis, prognosis and treatment of diseases.