The effect of daily temperature fluctuation on hematological, biochemical and coagulation parameters in Holstein cattle

Hematological and biochemical parameters, as livestock response indicator, can be used as a basis for diagnosis, treatment, and prognosis of diseases.  Blood samples were collected from 20 Holstein cows to investigate the effect of daily temperature fluctuation on hematological, biochemical, coagulation and hormonal parameters. Sampling was done three times per day that is in the morning, at noon and in the evening on a summer day in Nazarabad, Alborz province. RBC, Hb, HCT, MCV, MCH, MCHC, total and differential white blood cell (WBC) counts, AST, GGT, glucose, urea, total protein, albumin, fibrinogen, cortisol concentration, PT and APTT and platelet were measured.  Rectal temperature was measured at the same time of blood sampling. According to the results, there was an insignificant increase in RBC, Hb, HCT, MCV, MCH, MCHC, urea and cortisol in the second time of blood sampling (39Cº) compared to the other two times (The first time: 25Cº, the third time: 32Cº). Also, a significant increase in the total number of white blood cells, neutrophils, monocytes, total protein, albumin, AST, GGT and rectal temperature and a decrease in the number of eosinophils were observed in second sampling. No significant changes were observed in APTT, PT and platelet count. The evaluation of clinical indicators under heat stress showed a significant increase in rectal temperature. According to the results of this study, daily temperature fluctuation and mild heat stress can affect hematological and biochemical factors and should be considered for the evaluation and interpretation of hematological and biochemical profiles.