Blood haematological profile and meat colour of calves slaughtered in summer and autumn season.

The purpose of this study was to compare the haematological profile and meat colour of calves slaughtered in summer and autumn. The material covered 42 calves chosen randomly i.e. 22 slaughtered in summer (June-August) and 20 in autumn (October-December). Haematological analyses included haematocrit (HCT), haemoglobin level (HGB), red blood cells (RBC), white blood cells (WBC) and platelets (PLT). The morphology of the erythrocytes and platelets, and differentiation of leucocytes were examined. The colour of meat was evaluated instrumentally by Minolta CIE Lab* and haematin pigment content was determined. The blood haemoglobin content in calves in the compared seasons was similar (11.3 g/L) and found within a normal range. Blood of calves from the autumn season showed higher HCT, RBC, and MCV values with concurrent lower MCH and MCHC values in comparison to the summer season. Blood of calves slaughtered in summer showed a higher content of WBC and a significantly higher percentage of lymphocytes as against blood of calves from the autumn. Meat of calves from the summer season was paler (higher L* value), and had a significantly (p < or = 0.05) higher proportion of yellowness (b*). A brighter colour of meat from calves presented for slaughter in the summer season was noted along with a lower content of haematin pigments. Significant correlations were found between haematological variables (HGB, HCT and RBC, particularly) and haematin pigment content and meat lightness (L*) and redness (a*).