EFFECT OF SEASON CHANGES ON HAEMATOLOGIC PARAMETERS AND ERYTHROCYTE OSMOTIC FRAGILITY OF SAHEL BUCKS IN A TROPICAL SAVANNAH

Résumé

This study was aimed at evaluating the effect of seasonal change on haematologic parameters and erythrocyte osmotic fragility (EOF) as a biomarker of oxidative stress in male Sahel goats in the Northern Guinea Savannah zone of Nigeria. Blood samples were collected from ten (n=10) apparently healthy adult bucks in the peak of the cold-dry (CDS), hot-dry (HDS) and rainy (RAS) seasons. Meteorological parameters in the seasons indicated higher temperature-humidity index in the HDS (82.02), and RAS (82.83) compared with the CDS (75.25). The PCV and RBC of the bucks significantly increased (P < 0.05) during the HDS compared with the CDS. Similarly, during the HDS, the mean corpuscular volume (MCV) of the goats significantly decreased (P<0.05) compared to values obtained in the RAS. However, there was no significant change (P > 0.05) in other erythrocytic and leucocytic parameters between seasons. The EOF test indicated that the erythrocytes of bucks were significantly more sensitive (P < 0.05) to hypotonic haemolysis during the HDS as compared to the CDS and RAS. In conclusion, heat stress during the HDS significantly affected some haematologic parameters and EOF as compared to the other season, and the HDS seems to be the most stressful season to Sahel bucks.