by Daniela Gonzalez Carranza
Dystocia, or difficult calving, is not desirable, but it is an inevitable situation that we will have to face from time to time, and repercussions for cows and calves are complex. For example, even slight assistance can have an impact on production and fertility, not to mention on calf morbidity and mortality. Regardless of your calving management system, it is crucial to understand the process and stages of parturition.
What should we know about calving?
Cows go through three stages of calving, and it starts days before calving when the calf’s cortisol (stress hormone) triggers hormonal changes in the cow that initiates parturition.
The first stage refers to the cervix’s dilatation and can last between 4-24 hours, depending on parity. As hormones dilate the cervix, other signs begin to show, for example, the first one can be isolation, and as the time to calve comes closer, the cow displays other signs such as raising the tail, increasing laying bouts, and paying attention to the abdomen.
Once the cow is dilated and the calf is in delivery position, stage 2, which is delivery of the calf, starts. It is considered that stage two starts once the cow has frequent abdominal contractions (ideally 2-3 per minute) and the “water bag” (amniotic sac) is shown. The normal duration of this second stage can go anywhere from 30 minutes to 2 hours for multiparous cows and 3-4 hours for primiparous cows. Stage 2 ends when the calf is born. The third stage is the expulsion of the placenta.
Cow in Stage 2, notice the attention to abdomen and amniotic sac is shown.
When do I need to check?
Assisting calving can be challenging since each cow is different, and the process can be affected by various factors, including environmental conditions. However, here are some practical tips that can help determine whether intervention is necessary.
- Once you recognize the cow is in stage 2, check progress every 30 minutes. If you don’t know when the cow started stage 2, be patient and give time to monitor.
- If the cow is in stage 2 and there is no progress in 30 minutes, you could proceed to do a vaginal exam.
- If the cow is in stage 1 and there is no progress in 2-4 hours, you could proceed to do a vaginal exam.
- Keep in mind if the cow is still having uterine contractions (2-3 per minute).
How to do a vaginal exam?
When doing a vaginal exam, always remember these golden rules:
- Cleanliness: Prepare and clean the vaginal area of the cow to reduce the risk of infections.
- Lubrication: Lubrication helps with friction; less force is needed and decreases the risk of injuries to the cow and calf.
The first step is to evaluate the cervix dilatation. No progress will be made if the cow is not dilatated enough for the calf to go through. The next step is to evaluate the calf’s position or the reason for slow progress.
- What is the calf position, anterior (head first) or posterior (tail first)?
- Is the calf too big? Is the calf alive?
- Is there any obstruction?
- Is the water bag broken?
Calving workshops delivered by Cornell Cooperative Extension specialist.
- When identifying the front legs from the hind legs, two joints will flex in the same direction for the front legs. On the contrary, the two joints will flex in opposite directions for the hind legs.
- Always pull when the cow is having a contraction.
- When using chains, two loops (one above and one below the fetlock) will reduce the risk of injury for the calf.
- Rotation of the calf (90 degrees) can help avoid hip lock.
- When manipulating a leg inside the cow’s uterus, protect the calf’s hooves with your hand to avoid lacerations to the uterus.
There is no secret recipe for how to intervene in each dystocia, every case is different, and there may be difficult scenarios where you will need professional assistance from your veterinarian. Nonetheless, intervening calmly and precisely is crucial for a smooth transition into lactation, reducing injuries, and prioritizing the welfare of cows and calves.
Daniela González is a Dairy Management Specialist with the North Country Regional Ag Team from Cornell Cooperative Extension.
She earned her degree in Veterinary Medicine in Mexico City and her Master of Professional Studies degree from Cornell University in Animal Science with a concentration in dairy business management.
Daniela’s interests include reproduction, herd health, and business management.
Back in Mexico, Daniela worked on dairy farms as a veterinarian. She also collaborated with small and medium dairy farms in her community, allowing her to gain experience and interest in extension work.