I almost panicked when a farmer called me for assistance with a dystocia (difficulty in giving birth) case in a cow last holiday in the village.
When I’m faced with such cases I remember with anguish how I dislocated my shoulder while assisting a cow to deliver (I’m sure I will get over it soon enough though). But luckily my husband enthusiastically chipped in since he has assisted me in a couple of such cases and he finally managed to pull the calf out under my instructions.
As usual the case turned out to be unpredictable and difficult but it made me realise that if farmers know a few points on what to do in cases of dystocia, they might not need to call a vet at odd hours for assistance. This topic is very broad and it is better if we discuss it in two parts. Hence, this week we will discuss some finer points on what causes dystocia and how to diagnose and prevent it in cows, especially since this is the time of the year when most cows are giving birth. Next week we will continue with the actual difficult work of what to do if you are faced with a difficult birth.
There are many causes of dystocia, some can be prevented and others cannot. The causes of dystocia spring from many management choices ranging from breeding genetics and nutrition to management of the cow or heifer during delivery.
Breeding/genetics: Some cows have genetically big calves at birth but at times the foetus is too large or the cow’s pelvis is too small (this is especially common in the northern Namibian areas where some farmers are now using big framed bulls for their small Sanga cows). Thus, farmers should always be sure to breed heifers and small framed cows to bulls that are proven not to produce high birth-weight calves.
Nutrition: Dystocia commonly also occurs in over weight cows as too much fat around the pelvis can lead to a small birth canal. On the other hand, poor nutrition especially shortage of calcium causes decrease in the contraction of the uterus, making the cow becoming too weak to push out the calf or when the calf is born the cow will develop a condition called milk fever that paralysis the cow after birth. Thus the cow/heifer should be supplemented with enough calories to maintain body condition of 3.25-3.5 (we will discuss body condition scoring in details sometime later in our column) and foetal growth. This is the time I will once again advocate farmers to use multimin + selenium injection to cows one month before calving to reduce the risk of reproductive problems.
Abnormalities: A few times the uterus or cervix is twisted and then there is no way the calf would be delivered normally. Twins, abnormal position of calve during delivery and malformed calves tend to be difficult to deliver as well.
Thus, educating your personnel on the observation of the cows/heifers close to calving can result in early intervention that will help to prevent difficult birth. Most often, you have to call a veterinarian for assistance in such cases.
Cows versus heifers’ dystocia: Heifers often have dystocia more than in cows because the birth canal (mainly the vagina and vulva) does not stretch enough for the calf to be delivered. These dystocia can often be relieved by manually dilating the vagina and vulva by massaging them repeatedly at the onset of difficult birthing. The current recommendations to maximise profitability and decrease dystocia are to calf heifers at 24 months of age.
The big question is: when is a delivery a dystocia rather than a normal birth?
Knowing when to intervene and what to do is extremely important in difficult dystocia and prevention of calf death.
The cow is on average pregnant for 280 days (about nine months). As a rule of thumb, if the amniotic sac (the water bag that covers the baby calf) appears at the vulva, then the calf should be born within 1-2 hours. Another rule of thumb is that cows are expected to deliver 30-60minutes and heifers 60-90 minutes after they are in active labour or the calf feet show. A cow that is frequently trying to urinate or walks with the tail up for more than 3-4 hours may have a twisted uterus or an abnormally positioned calf that is blocking the passage of the foetus. If you do not know when the cow started labour but the cow appears restless, nothing is showing, she is getting up and down and straining very little for like more than five hours, you should be getting worried and examine the cow.
Dystocia can have a large economic impact on farmers due to calf death, injury or death to the cow, veterinary cost, as well as the decrease in pregnancy rates of the cow after losing a calf. Therefore, a good management program to reduce dystocia and rapid identification of cattle experiencing dystocia is critical to cattle welfare and farm profitability.
Don’t miss out next week when we will discuss how to pull that difficult calf out!