The Struggle is Real: Stage One of Parturition
I know this may sound weird, but cows are stealthy. Cows try to hide their difficulties and shield their struggles in order to stay safe from predators. Calving is no exception. I can walk into the calving barn and all cow eyes will be on me; nobody moves; they all act as if I caught them doing something sneaky. They do not want me to know what they are up to, especially if they are calving. Rear ends are spun away from me, hiding their surprises. They just want me to go away, so they can get back to whatever it is they were doing. With the installation of video surveillance cameras, I can secretly watch them as they behave more normally, thinking they are alone. Who is stealthy now? So, what are we really watching for in a normal versus an abnormal calving? Let’s start with the three stages of parturition, followed by a focus on stage one problems.
1st stage: presentation of the calf into the vaginal vault
2nd stage: expulsion of the fetus
3rd stage: passing of the placenta
The hours leading up to calving can be quiet and secretive, especially for a veteran cow. She may simply start to isolate herself as her body prepares to go into labor or stand happily at the rail eating as if nothing is happening. Remembering that the first stage of parturition prepares the cow for calving, all in the span of about 6 to 24 hours (sometimes days). Small, rhythmic uterine contractions bring the calf up into the vaginal vault. Under the hormonal influence of estrogen and relaxin, the reproductive tract becomes lubricated and softened. Producers may certainly note the springy vulva, the dropped pelvic muscles and the change in the abdominal shape as the calf begins to move up and back. However, sometimes the signs of stage one of parturition are not noticeable at all. Once the cervix is thinned and dilated, the calf moves up into the vaginal vault, creating the needed pressure that signals the start of stage two. Unfortunately, stage one doesn’t always go as planned. In fact, many catastrophes can occur during stage one. But if stage one is so quiet and unsung, how do we recognize any problems? A short list of symptoms to look for includes:
Common things occur commonly. Malpositions such a breech, backwards, head down, tangled twins or bizarre transverse presentations can all fail to present the calf in the necessary conical position to initiate the second stage of labor. Metabolic dysfunction (low calcium or phosphorus), uterine torsion and failure of the cervix to dilate can also lead to failure to move into the second stage of labor. No matter the cause, a cow in trouble, may just be standing around, looking at you; stealthy.
Cows that fail to properly present their calf into the vaginal vault make up the smallest percent of my calving emergencies. However, because the calf does not signal the obvious telltale signs of calving, stage one failures are easy to miss. These cows often fail to lay down to begin abdominal contractions. They may pace, bellow and seem anxious. Or, blood may be the only symptom of trouble brewing. Cows typically repeat their calving behaviors from year to year. If you sense something is wrong, you are probably right.
About the Author
Dr. Colleen Lewis is a 1996 graduate of Kansas State University, College of Veterinary Medicine. Her career has taken her to many places as a practice owner, consultant, embryologist, and mentor. She enjoys mixed animal practice, teaching, traveling, farming and high school sports with her husband, Andrew and their three boys.