To send a message to an author, click on the author's name at the end of an article. These data show that dystocia is the single largest cause of calf losses. To decrease these losses, you need to understand the birth process and be able to recognize normal calving so that calving assistance can be given when needed. Calving Stages Stage Events Duration 1. Preparation Calf rotates to upright position.
Uterine contractions begin.
Cervix begins to dilate, allowing water sac to protrude. 2 to 6 hours 2. Fetal Expulsion Cow usually lies down and fetal contractions begin. Fetus enters birth canal. Front feet and head protrude first.