Matthijsen H F, Borst G H
Tijdschr Diergeneeskd. 1983 Nov 1;108(21):829-30.
Gestation continued for 324 days in a cow pregnant for the fourth time. This extreme prolongation could be due to congenital abnormality in the calf consisting in aplasia of the pituitary and anencephaly.
一头经产母牛的妊娠期持续了324天。这种极度延长可能是由于犊牛先天性异常，表现为垂体发育不全和无脑畸形。
