Histological findings in placentomes of cows with retained placenta

Placentomes were obtained immediately after calving from 34 cows with retained placenta and 19 cows with normal placental release. All cows had a normal duration of pregnancy. In placentomes from cows without retained placenta the lack of cryptal epithelium and a small number of binucleate cells was noted. In the group with retentio secundinarum, 73.6% of the cows had delayed maturation of placenta (presence of cryptal epithelium and numerous binucleate cells), 17.6% had placentitis (infiltration of leucocytes) while 8.8% showed proliferation of connective tissue of caruncles. Thus, the major cause of disturbances in placental release was the delayed maturation of placenta.