By Glenn Selk, Oklahoma State University Emeritus Extension Animal Scientist
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. Locate and notify someone to assist you before the “pulling” begins.
If the hips are causing severe resistance, pull with the chains crossed in order to cause a quarter turn of the hips. This quarter turn will align the widest part of the hips with vertical axis of the pelvic opening. The vertical axis of the pelvic opening is greater than the horizontal axis. 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. If you discover that the calf’s legs are also still not through pelvic opening and all you can feel is the calf’s tail (a breech presentation), then call your local veterinarian immediately. A breech presentation often requires a spinal block or caesarian section to deliver the calf.
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