Effect of seasonal variations in Mediterranean area on haematological profile in dairy cow

The aim of this study was to investigate the effects of seasonal variations in Mediterranean area on haematological parameters in ten dairy cows (Bruna breed) kept under natural photoperiod and temperature. On blood samples, collected through an external jugular venipuncture every 30 days for 12 months, haematological profile was performed using an automatic multiparametric analyser for haematology. Red blood cell (RBC), white blood cell, haemoglobin (Hb), haematocrit (Hct), mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, platelets (PLT) and plateletcrit (PCT) were measured. One-way for repeated measure analysis of variance showed a statistically significant effect of time of year (P < 0.05) on RBC, Hb, Hct, PLT and PCT. The majority of the haematological values obtained, comparable to the values considered to be normal for dairy cows, showed that seasonal variations in haematological parameters are related to changes in physical environment with particular emphasis on ambient temperature, relative humidity and temperature-humidity index. These parameters need further investigations in relation to age and sex differences with particular attention to reproductive status.