By Sarah Eaton, DVM, DACT

Spring calving is the rancher’s reward for a cold, dark spring feeding in the snow. 

Careful bull selection, timing for bull turnout, and good vaccine and deworming protocols are all building blocks of a good calf crop. 

At calving time, however, it is important to know the normals and the abnormals so that a cow or heifer can be helped when necessary. Labor proceeds in three stages, and the length of each stage depends on the species of animal. 

Stage 1 of labor is when the cow and fetus prepare for the calf to be born. In the cow the cervix relaxes and begins to dilate. The cervix starts to dilate due to increased cervical tone and then dilates even further due to pressure from the calf’s head and front legs. Stage 1 labor lasts on average 6 hours but may last up to 24 hours in heifers. 

Stage 2 of labor occurs when the dam has abdominal contractions that push the calf into the cervix and through the vaginal canal. The end of stage 2 labor is marked by the complete birth of the calf. The average length of time for stage 2 labor in cows is 2-4 hours but can last longer in heifers.   

The third stage of labor is passage of the placenta.  On average the placenta takes eight hours to be expelled but it is not considered retained until 12 hours after birth. 

Dystocia, or a problem birthing, can occur in cows and heifers due to many causes.  In the uterus calves can tangle themselves and not be in the right position to exit through the cervix. The legs, body, and head must sometimes be moved within the uterus to align the calf to come out, either head first or back legs first. 

If there are twin calves their legs and bodies may need to be untangled to prevent a jam at the cervix. The most common cause is a large calf and a small dam. If the calf is excessively large it must be removed from the dam by cesarean section.  Smaller large calves can sometimes be pulled with lubrication and traction. 

Care should be taken to not pull too hard on the calf as that can hurt the dam or the calf. By working together the producer and veterinarian can help the spring calf crop be born easily and healthy.