Hematological changes during pregnancy and lactation in Pelibuey ewes infected with gastrointestinal nematodes

The objective was to determine the hematological parameters associated with physiological stages, type of lambing, age, and susceptibility in ewes infected with gastrointestinal nematodes (GIN). Forty-six Pelibuey ewes of 1.5–4 years of age and naturally infected with GIN were sampled during pregnancy and lactation. Fecal nematode egg counts (FECs) were determined and blood samples obtained to determine the hematocrit (HCT), peripheral eosinophil count (PEC), total plasma protein (TPP), and immunoglobulin A level (IgA) in plasma . Hematological variables were measured in a MEDONIC analyzer. The variables were analyzed using mixed models with the SAS software. The FEC showed higher values ( P < 0.01) in early lactation (1,053 ± 2,064 eggs per gram of feces, EPG) compared with early and middle pregnancy (50 ± 199 and 171 ± 302 EPG). At middle pregnancy, most erythrogram components showed high values (HCT 33.8 ± 4.5%; red blood cell count (RBC) 9.2 ± 1.2 × 10 9 /mL; mean cell volume (MCV) 36.9 ± 5.5 fL; hemoglobin (HGB) 11.6 ± 1.1 g/dL), whereas at late pregnancy and during lactation, the values decreased. The lowest values were recorded in late lactation (HCT 25.7 ± 5.0%; RBC 8.2 ± 1.9 × 10 9 /mL; MCV 31.6 ± 7.9 fL; HGB 10.0 ± 1.7 g/dL). White blood cell counts gradually decreased during pregnancy and lactation, with the lowest values in late lactation (10.5 ± 2.8 cells 10 6 /mL). In the immune response, the PEC (0.91 ± 0.39 cells 10 6 /mL) and IgA (14.4 ± 14.9%) increased in late lactation. It was concluded that is necessary to consider the physiological state and age, litter size, and natural resistance of the ewes to conduct control activities against GIN.