Serum Copper and Haematological Values of Sheep of Different Physiological Stages in the Dry and Wet Seasons of Central Trinidad

A study was conducted to determine serum copper (Cu) concentrations and hematological values of 174 sheep from four medium sized farms, pertaining to physiological stage, in the late dry and late wet seasons of Central Trinidad. Serum Cu was significantly lower in the dry than in the wet season (P < 0.001) with a corresponding high percentage of samples with low Cu levels in the former. 31% of dry nonpregnant sheep exhibited a nonregenerative anaemia. Also, hemoglobin and packed cell volume values varied (P < 0.001) including lymphocyte (P < 0.01) counts, among growing animals compared with other physiological stages. Significant variations also occurred among neutrophil (P < 0.05) and eosinophil (P < 0.05) values in sheep. Highest haemoglobin and packed cell volume, white blood cell counts, and lymphocyte values in growing sheep compared with other stages were probably age related.