Assisting the Posterior Presentation (Backwards Calf)

by Glenn Selk, OSU Extension Animal Reproduction Specialist

Any cow calf producer that has spent several years in the cattle business has had the experience of assisting a cow or heifer deliver a calf that was coming backwards. Understanding the physiology and anatomy of the calf and mother will improve the likelihood of a successful outcome. Study the diagram of the “posterior presentation” shown below.

Note the relative positions of the tailhead of the baby calf and the umbilical cord that connects the calf to the mother’s blood supply. As the calf’s hips are pulled through the pelvic opening, the baby calf’s tail will reach the outer areas of the mother’s vaginal opening. Once a person can see the baby calf’s tailhead, the umbilical vessels are being compressed against the rim of the mother’s pelvic bone. The blood flow, exchanging oxygen and carbon dioxide, between calf and mother is greatly impaired, if not completely clamped off. Research, many years ago, conducted in Europe illustrates how little time it takes to compromise the calf’s survivability when the umbilical cord is clamped. These scientists studied the impact of clamping the umbilical cord for 0, 4, 6, or 8 minutes.

Table 1. Impact of clamping of umbilical vessels on calf survivability

Duration of Clamping	Number of Calves	Fate of Calves
0 minutes	5 calves	All of the 5 calves lived
4 minutes	5 calves	4 lived; 1 died
6 minutes	3 calves	3 died
8 minutes	3 calves	3 died

Certainly, if a producer does not feel confident in their abilities to deliver the backward calf, call your veterinarian immediately. Time is of the essence. As producers examine heifers or cows at calving and find a situation where the calf is coming backward, they need to keep this European data in mind. If the calf’s hips are not yet through the pelvic opening, they have a little time to locate help and have someone else to aid in the assistance process. Once the cow and the producer in concert have pushed and pulled the calf’s hips through the pelvic opening and the tailhead is apparent, the calf needs to be completely delivered as quickly as possible. The remainder of the delivery should go with less resistance as the hips are usually the toughest part to get through the pelvic opening. The shoulders may provide some resistance. However, some calf rotation and traction being applied as the cow strains will usually produce significant progress. Remember, the completion of the delivery is to be accomplished in about 4 minutes or less. The calf’s head and nostrils are in the uterine fluids and cannot breathe until completely delivered. The calf must get oxygen rapidly to offset the hypoxia that it is been subjected to during the delivery. After the calf is delivered, tickle it’s nostrils with a straw to cause snorting and inhalation of air to get it started to breathing.