The periparturient period ranging from 3 wk before calving to 3 wk after calving presents enormous physiological challenges for the dairy cows. It is a period that is affected by metabolic stressors, major changes in endocrine status and altered immune function which together results in an increased risk of diseases including hypocalcaemia, ketosis, hepatic lipidosis, laminitis, mastitis, retained placenta and metritis. The present investigation was undertaken in Central Cattle Breeding Farm, Central Research Station, BAIF, India to study the hematological changes in puerperal period in 30 cows of HF pure, JE pure and their crosses under tropical conditions to compare the Hgb, TLC and CBC/diff. count 10 d before and 10 d after parturition to assess the extent of metabolic changes, infection and stress. The results were analyzed using ANOVA. The study revealed a nonsignificant difference and decrease in the Hgb count from 11.41 ± 0.30 to 10.59 ± 0.30 which may be due to the increased blood supply to fetus and milk adipose tissues with hemorrhagic loss during calving. The TLC count displays a significant (P < 0.05) increase from 8.57 ± 0.39 to 10.00 ± 0.58 in postpartum period confirming the reports of previous studies which states that there is a decrease in immunity level due to stress and rise in infection. Neutrophil count increased from 47.03 ± 1.77 to 51.27 ± 2.14 nonsignificantly as the infection in postpartum period may rise. Eosinophil count, Lymphocyte and monocyte level did not reveal any significant changes. It can be concluded that due to lower hemoglobin, hemorrhagic stress and lower immunity due to rise in infection, the animal’s health and production are always under threat; hence careful attention is required during the periparturient period. Table 1. Blood parameters in Holstein cows 3 wk pre- and post-calving

Parameter	Hgb (g %)	TLC (×103)	Neutrophil (%)	Eosinophil (%)	Lymphocyte (%)	Monocyte (%)
Pre	11.41 ± 0.30	8.57 ± 0.39	47.03 ± 1.77	6.07 ± 0.43	44.03 ± 1.86	2.73 ± 0.17
Post	10.59 ± 0.30	10.00 ± 0.58	51.27 ± 2.14	5.57 ± 0.42	40.70 ± 2.18	2.53 ± 0.20
“F”	0.0572	0.0454	0.1299	0.5808	0.2494	0.5318