SEASONAL AND SPECIES VARIATIONS IN ERYTHROCYTES OSMOTIC FRAGILITY OF INDIGENOUS POULTRY SPECIES IN ZARIA, NORTHERN GUINEA SAVANNAH ZONE OF NIGERIA

摘要

A total of one hundred and twenty blood samples were obtained from apparently healthy indigenous chickens, guinea fowls, ducks and pigeons for the determination of erythrocyte osmotic fragility (EOF) The EOF was determined in hypotonie saline solutions spectrophotometrically during the harmattan, hot and rainy seasons. The EOF was higher in the chicken and guinea fowl with minimum and maximum resistance occuring in ranges of 0.65 - 0.75 and 0.25 - 0.35 per cent sodium chloride (%NaCI) concentrations,respectively it was lower in the pigeon in which the minimum and maximum resistance occurred in ranges of 0.45 - 0.65 and 0.15 - 0.25% NaCl concentrations, respectively. The derivative fragiiigrams of chicken, guinea fowl and duck were unimodat, while that of the pigeon was bimodal. In all the indigenous poultry species, the érythrocytes were more fragile to osmotic lysis during the hot season than the other two seasons. It was concluded that during the hot dry season, hypotonie stress of the érythrocytes should be reduced to the barest minimum in these indigenous poultry species, in order to prevent hypotonie haemolytic anaemia.