In all 14 Red Kandhari cows of group-I and group-II, allantochorion
appeared as first water bag.
DNA was extracted from the allantochorion
of the placenta and analyzed as described (2).
Embryonic viability was estimated by the macroscopical characteristics of the embryonic membranes, degree of vascularization of the allantochorion and embryo development, according to that described by Boshier y Guillomot [3, 8].
Thirty six percent of them were classified as non-viable, based on at least 1 of the following macroscopic characteristics: absence of blood vessels in the allantochorion, yellowish colour of embryonic membranes and absence of an embryo.
Eventually the allantois fuses with the chorion to form the allantochorion
(also known as the chorioallantoic membrane), the membrane that becomes the fetal component of the placenta.
Although, there are some early reports (Vandeplassche et al., 1971) of high mortality rates of both mare (40%) and fetus (71%) using this non-surgical method, possibly because of separation of allantochorion
from endometrium with subsequent abortion, premature birth, uterine rupture and death of fetus.
Once the fetus is in the birth canal, the allantochorion
ruptures and releases fluid ("breaking water").
Though non-surgical method are associated with high mortality rate of both mare (40%) and fetus (71%), possibly because of separation of allantochorion
from endometrium with subsequent abortion, premature birth, uterine rupture and death of fetus (Vandeplassche et al., 1972).
The extra-embryonic membrane that forms when the allantois and chorion fuse.
Purvis (1972) also recommended manual rupture of allantochorion
if it has not ruptured naturally by the time the foal had advanced well into the vagina.
A 6-year-old graded Murrah buffalo in third calving was presented with history of term completion and straining since 24 hrs and difficulty in delivery of fetus with rupture of allantochorion
noticed 12 hr back.
In general, prolapse occurs when membranes are being removed and due to traction applied to allantochorion