Have you ever had a cow that was in stage one of labor but never advanced to stage two? The calf was coming in a normal position and was not a breech, but it did not advance to stage two of labor after four or five hours.

The cow may not be identified as having problems. She shows little outward signs of labor other than abdominal discomfort. You decide to go ahead and provide assistance.

The calf probably pulled easily once you got the fetus up into the pelvic area. The cow should have delivered the 80-lb. calf with no problem.

Bill Kvasnicka, University of Nevada-Reno Extension veterinarian, says what you saw was probably due to “uterine inertia.”

“This condition is rather rare and is more common in mature cows than in heifers,” he says. “Simply put, the uterine muscles fail to contract during labor, and the calf stays in the body cavity.”

Failure of the uterine muscles to contract does not move the fetus into the pelvic area or birth canal. Thus the calf never triggers stage two of labor. Consequently, the cow never delivers the calf herself and assistance is necessary.

Ranchers often initially diagnose this condition as a breech birth because of the lack of outward signs of labor, explains Kvasnicka.

“Upon inspection, you find out it actually was uterine inertia. The calf is coming in a normal position, but the cow never gets down to work on delivering the calf.”

Stages of calving
Stage & time Events
Stage 1
preparatory
(2 to 6 hours)
1. Calf rotates to upright position.
2. Uterine contractions begin.
3. Water sac is expelled.
Stage 2
delivery
(1 hour or less)
1. Cow is usually lying down.
2. Fetus enters birth canal.
3. Front feet and head protrude first.
4. Calf delivery completed.
Stage 3
cleaning
(2 to 8 hours)
1. Placental attachments relax.
2. Uterine contractions expel membranes.
Source: University of Nebraska

Kvasnicka says close observation of cows and being able to recognize odd behavior is paramount to saving calves with delivery problems such as uterine inertia or complete breeched births.

Normal calving can be divided into three general stages — preparatory, fetal expulsion and expulsion of the placenta or afterbirth. The time interval of each stage varies among types and breeds of cattle and among individuals of the same breed.

Although the exact stimulus that initiates parturition is unknown, it does involve hormonal changes in both the cow and fetus, as well as mechanical and neural stimulation in the uterus.