The present study was carried out of the Experimental station belonging to
the Department of Animal Production, Faculty of Agriculture, AI- Azhar University.
Blood samples were taken from 23 pregnant buffaloes at 60 days prepartum every 15
days, at parturition and until 90 days postpartum. Serum cortisol. T3 and T. were
assayed. Cortisol level was almost constant and increased (P< 0.05) steadily at
parturition, After parturition was declined then increased until 90 days, postpartum.
Concentration of cortisol was lower in buffaloes which had did not exhibit estrus than
buffaloes which had exhibit estrus. Statistically non-significant. Triiodothyronine (Tal
and thyroxine (T.) showed no significant from 60 days prepartum until 90 days
postpartum. However. the levels of T3 and T4 were increased gradually towards
parturition. After parturition were decreased and fluctuated until 90 days postpartum.
In buffaloes which had exhibit estrus, The levels of T 3 and T 4 were higher. non-
significant, than buffaloes which had did not exhibit estrus.