When a cow or heifer has difficulty calving, it is usually due to the calf being too large or the cow’s pelvis being too small. When this occurs veterinary assistance may be required. To know what is normal and when assistance is required a general knowledge of the birthing process is needed.
The Birthing Process
As with all mammals there are stages of the birthing process.
Stage 1: This is the preparation stage when the calf moves into the birthing position (head first) and the birthing canal dilates and opens. This can be indicated by a string of mucus coming from the cow’s vulva and often by signs similar to colic due to a level of discomfort felt by the cow. At this stage the cow will often isolate herself and will walk with her tail up in the air. This stage usually lasts between 3 to 6 hours but can last up to 24 hours in heifers.
Stage 2: This is active labour, i.e. when the water breaks and the calf is delivered. Normal calf delivery is front feet first followed by the head and the body thereafter; this is known as cranial presentation. This stage commonly last 30 to 50minutes but can take up to 4 hours in heifers, however any longer than 2 hours in older cows who have previously had calves is abnormal. During this stage the cow often lies flat on its side and contractions are seen with the straining of the abdominal muscles.
Stage 3: This phase is the passing of the membranes and should take no longer than 12 hours. Normally this phase lasts around 30 minutes to 3 hours.
When Assistance is Required
If a cow is walking with her tail up in the air for more than 12 hours and seems to be in discomfort, then it is recommended that she be examined. This delay may indicate the calf is in the wrong position or the canal has not dilated enough. Other more severe circumstances may be possible in this situation as well.
If the heifer has been straining (in active labour) for more than 4 hours and a calf has not been delivered than assistance is required. In a cow if the straining lasts for more than 2 hours without delivery than assistance is required.
If you do not know the commencement time of straining and the cow has been straining for more than 40 minutes without progress (e.g. the forelimbs are all that is seen at first observation and at second observation that is all that is seen again) then assistance is required.
If the calf has been successfully delivered but the membranes are retained (visibly hanging out of the vulva) after 48 hours then assistance is required.
The need for veterinary assistance will depend on the level of experience of the assistant/grazier. Generally if you have been trying to deliver the calf for more than 20 minutes without success then veterinary assistance will be required. If circumstances mean financial or geographical restraints are involved than humane euthanasia may be indicated to reduce suffering for both cow and calf. The use of tractors, vehicles or other machines to assist calvings are a thing of the past and can cause severe damage and pain to both cow and calf and are more often than not inhumane.
If you require assistance with a cow having difficulty calving, please phone the clinic on 074681 1523 (all hours). Our vets are more than happy to help. Please don’t let your animals suffer.