Dynamics of hematological parameters in female lambs during the first four months of life / Dinâmica dos parâmetros hematológicos em cordeiras durante os primeiros quatro meses de vida

ABSTRACT

Important physiological changes affect the blood profile of ruminants during the growth phase, but few studies approach the factors involved in these dynamics in lambs. The aim of this study was to characterize the dynamics of hematological parameters, of total plasma protein (TPP), and of fibrinogen in healthy female lambs during the first four months of life. Blood samples of 35 female lambs were collected at 30, 60, 90, and 120 days old to perform the complete blood count (CBC). The erythrocyte and leukocyte parameters, TPP, and fibrinogen were determined. The means for total red blood cell (RBC) counts at 60 and 120 days differed (P < 0.05) from the initial mean, showing a peak of 13.6 x 106 cells μL-1 at 60 days old. The mean values for packed cell volume (PCV) and hemoglobin (Hgb) concentration increased (P < 0.05) until 90 days and decreased at 120 days (36.6% to 33.7% and 11.4 g dL-1 to 10.6 g dL-1 between 90 and 120 days, respectively). The means for mean corpuscular volume (MCV) and for mean corpuscular hemoglobin concentration (MCHC) increased (P < 0.05) between 30 and 120 days (27.5 μm3 to 29.7 μm3 and 26.6% to 31.4%, respectively). The total white blood cell (WBC) count increased (P < 0.05) and reached a peak at 90 days (9,314 cells μL-1). The peaks for segmented neutrophils (5,141 cells μL-1) and lymphocyte counts (4,236 cells μL-1) occurred at 60 and 90 days, respectively. The means for neutrophil/lymphocyte ratio were similar (P > 0.05) between the ages (mean of 1.8) but higher than the reference value for adult sheep (0.5). The initial mean for eosinophil counts (2 cells μL-1) was lower (P < 0.05) than all subsequent ones, and the monocyte count showed the lowest level (P < 0.05) at 120 days (232 cells μL-1). The mean for TPP at 60 days (6.4 g dL-1) was higher (P < 0.05) than the other ages.(AU)

RESUMO

Important physiological changes affect the blood profile of ruminants during the growth phase, but few studies approach the factors involved in these dynamics in lambs. The aim of this study was to characterize the dynamics of hematological parameters, of total plasma protein (TPP), and of fibrinogen in healthy female lambs during the first four months of life. Blood samples of 35 female lambs were collected at 30, 60, 90, and 120 days old to perform the complete blood count (CBC). The erythrocyte and leukocyte parameters, TPP, and fibrinogen were determined. The means for total red blood cell (RBC) counts at 60 and 120 days differed (P < 0.05) from the initial mean, showing a peak of 13.6 x 106 cells μL-1 at 60 days old. The mean values for packed cell volume (PCV) and hemoglobin (Hgb) concentration increased (P < 0.05) until 90 days and decreased at 120 days (36.6% to 33.7% and 11.4 g dL-1 to 10.6 g dL-1 between 90 and 120 days, respectively). The means for mean corpuscular volume (MCV) and for mean corpuscular hemoglobin concentration (MCHC) increased (P < 0.05) between 30 and 120 days (27.5 μm3 to 29.7 μm3 and 26.6% to 31.4%, respectively). The total white blood cell (WBC) count increased (P < 0.05) and reached a peak at 90 days (9,314 cells μL-1). The peaks for segmented neutrophils (5,141 cells μL-1) and lymphocyte counts (4,236 cells μL-1) occurred at 60 and 90 days, respectively. The means for neutrophil/lymphocyte ratio were similar (P > 0.05) between the ages (mean of 1.8) but higher than the reference value for adult sheep (0.5). The initial mean for eosinophil counts (2 cells μL-1) was lower (P < 0.05) than all subsequent ones, and the monocyte count showed the lowest level (P < 0.05) at 120 days (232 cells μL-1). The mean for TPP at 60 days (6.4 g dL-1) was higher (P < 0.05) than the other ages.(AU)