Résumé:
The influence of different intrinsic and extrinsic factors on hematological parameters has been the subject of several previous works around the world. In Algeria, studies about all these factors in dairy cows are quite rare. It would therefore be interesting to provide for the veterinarians the usual values, in order to help them in the subclinical phase of the diagnosis. The first part is a bibliographical summary on blood physiology in cattle, the second part is an experimental study. A first section establishes the usual values of hematological parameters (RBC, HGB, HCT, MCV, MCH, MCHC, PLT, WBC, Number of LYM, MONO, NEU, EOS and BASO) and ionic elements (Na, K, Cl, Ca and P) in cattle, as well as the
correlation between these parameters and the intrinsic factors (age, breed, gender and physiological stage). Overall, the values are within physiological norms. For intrinsic factors, the variations are significant for age for all parameters of red and white blood cells. Concerning breed, only number of NEU is significantly different. For gender, the levels of PLT as well as some erythrocyte indices (MCH, MCHC) are the only variables. Finally, for the physiological stage, all the parameters studied fluctuate significantly between stages, excepting HGB, PLT, number of EOS, BASO and Na. The second part studies the influence of extrinsic factors (season and breeding methods). The results show a significant influence of the season on all parameters of red and white line except RBC, HGB and MCV. The breeding method has a significant influence on HGB, HCT and number of EOS.
