The calving season comes with many unknowns, including weather, timing, and much more. Livestock producers also know you can rarely predict when cows will calve – though it usually seems to coincide with poor weather. Being prepared can make the difference in having a live or a dead calf. It is also important to know when to intervene in calving and knowing the signs that should make you concerned for your herd.
Stages of calving
Most species have three labor stages, all with notable signs. The first stage of calving is the dilation of the cervix, which begins between 2 – 24 hours before the actual expulsion of the calf. Many hormones play a role in calving, and during this stage, the “progesterone block” is removed, and the uterine muscles begin to become more sensitive. This stage often goes unnoticed, but cows may become more isolated or appear in discomfort. Towards the end of stage 1, cows may raise their tailhead, move their tail, and have increased discharge. The ligaments will soften near their pin bones, so they may appear sunken in. The udder will also appear full during this stage, as the colostrum production is peaking.
Stage 2 is the actual delivery of the calf. It will begin with the movement of the membranes and calf into the pelvic canal and is complete once the calf is delivered. Stage 2 can typically last from 1 – 6 hours. In heifers, this stage will take longer. This stage can be very quick in older, more mature cows, sometimes just 20-30 minutes. This stage has the greatest possibility for problems, especially with twins, large calves, or abnormal presentations.
Stage 3 is the delivery of the placenta and membranes and typically occurs less than 8 to 12 hours after the calf’s delivery. If the placenta does not deliver 12 to 24 hours after the calf, it is considered a retained placenta. Intervention is encouraged with a retained placenta. Retained placentas increase the risk of metritis or infection of the uterus, so it is encouraged to monitor these cows closely.
Calving presentations
The majority of cows give birth without assistance or issues. Still, it is important to recognize what is normal and abnormal in calving. Correct positioning is an anterior presentation, where the front legs are presented first, with the head of the calf in between the front legs. If the calf is correctly positioned and the cow is not in distress, do not intervene. Unnecessary intervention can cause more harm than good and increase the likelihood of calf death.
Incorrect positioning includes a posterior presentation, where the calf’s hind legs are presented first. Calves presented posteriorly should be pulled immediately after ensuring the cow’s cervix is dilated. There are multiple other presentations that are abnormal, and you should call a veterinary professional to assist with delivering the calf, to protect both the cow and calf. If you are going to pull a calf, ensure the vaginal cavity is appropriately lubed, and force is gentle but consistent.
Supplies and assistance
No matter the situation, it is important to be clean and gentle. Excess force can cause significant harm to the cow and calf. In preparation for calving season, have the following supplies on hand:
- OB gloves
- Lube (use lots)
- Bucket for warm water
- Iodine
- Calving chains
- Towels
- IV supplies
- Calcium
- Syringes and needles
- Electrolytes
- Feeding tubes
- Colostrum replacer
After a calf is delivered, ensure the calf is properly dried off, especially in cold and windy weather. The calf should get high-quality colostrum, so keep replacement colostrum on hand to supplement if necessary. If the calf and cow have a difficult birth, supplying electrolytes can help keep the cow and calf hydrated. Dip the calf’s navel with iodine. Give oral or IV calcium promptly if you suspect milk fever or hypocalcemia.
Early intervention is key for calving. When you first notice a cow is calving, check the presentation to ensure the calf is presented properly. If the presentation is abnormal, contact a veterinarian as soon as possible. Use clean supplies and disinfect with iodine. When dealing with calving cows, move slowly and be quiet to avoid causing more stress to your cows. Be careful, as calving cows can be unpredictable. When in doubt, contact your veterinarian.
Resources:
UW-Madison: Three Stages of Bovine Parturition