Influence of lactation stages on haematological and biochemical parameters in blood of Lacaune dairy sheep

The research objective was to determine haematological and biochemical parameters in blood of 30 Lacaune dairy sheep during different stages of lactation (early: 60th, medium: 120th and late: 180th days). The sheep were on average 4 years old, in 3rd lactation. Haematological parameters were determined in whole blood (white blood cell (WBC), red blood cell (RBC), haemoglobin (HGB) concentration, haematocrit (HCT) value, mean corpuscular volume (MCV), mean cell haemoglobin (MCH), mean cell haemoglobin concentration (MCHC) and platelet (PLT) count), and a blood smear was used for determination of differential blood cell count. Determined biochemical parameters in blood serum were: concentration of minerals (Ca, P-inorganic, Mg and Fe), concentration of total proteins (TP), albumin (ALB), globulins (GLOB), urea, glucose (GUK), cholesterol (CHOL), high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglycerides (TGC), beta-hydroxybutyrate (BHB) and non-esterified fatty acids (NEFA), enzyme activities (aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), γ-glutamyl transferase (GGT), creatine kinase (CK), activity of glutathione peroxidase (GPx) and total superoxide dismutase (SOD). With progression of lactation stages, sheep blood tests proved significant increase in WBC, RBC, HGB, HCT, monocytes, Fe, urea, TP, ALB, CHOL, HDL, LDL, BHB, AST, GGT and ALT as well as a decrease in lymphocytes, Mg, GUK and SOD. Determined changes in haematological and biochemical blood parameters of Lacaune dairy sheep during different lactation stages proved good quality nutrition of sheep and indicate the need to include this dairy breed/genotype in prospective schemes for definition of referential values for these indicators in sheep.