Vet Margins: Calving risks for dairy and beef herds

Ideally, cows calve in a clean, dry environment themselves, without any assistance from the farmer, however undoubtedly, problems and situations do occur when early intervention and assistance is needed for a successful outcome.

Selecting the best heifers and an easy calving bull can avoid many calving difficulties. Pre-breeding checks and pelvic scoring have been shown to reduce heifer calving problems, but nutrition and bull selection has by far the most significant effect on calving ease.

Caesarian sections are more likely to be successful if the cow/heifer is in a clean, dry environment and there is clean water available

Normal labour is split into two important stages. Stage 1 is when the cervix starts to open, cows naturally seek isolation, restless, swishing or raised tail and a vaginal discharge. Stage 1 can take up to six hours or up to 24 hours in heifers.

Stage 2 is the actual delivery, once the cervix is fully dilated and the calf has started to enter the birth canal. This can take between 30 minutes and four hours but again may be longer in heifers. Investigation should occur if the water bag appears, and no progress has been made within hours or straining has taken place for 30 minutes without progress. Remember, safety comes first – only attend to cows if safe to do so.

If you don’t think you can get the calf out without injuring the cow or the calf – call the vet.

Cleanliness is vital, keep the tail out of the way, clean around the vulva, wear clean gloves and use plenty of lubrication from the start.

On first examination, check if the cervix is sufficiently dilated for delivery. If not, leave for 30 minutes and re-examine. If still not dilated, call the vet.

Is the calf presented normally, head and two front feet? Is the head and feet in the pelvic canal with plenty of room above the head? Can you pull the fetlocks outside the vulva and front legs NOT crossed? Initially pull horizontally until the shoulders are out then down at 45 degrees. Ideally use human power together with contractions from the cow. Calving jacks must be used with care, as they can injure both the cow and the calf.

If difficulty occurs, the calf may be too big and need to call the vet. A backwards presentation, if hind feet are presented (soles of feet upwards) Stage 1 labour may take longer and require assistance. Can the hocks be pulled outside the vulva? Pull slightly upwards until the tail head is out, then pull downwards. If traction is required without any progress, the calf may be too big and need to call the vet.

Breach presentations, where you can only feel a tail can be risky to correct. These are more likely with twins and often be in Stage 1 labour for a long time and may well be a dead calf. If the legs are easily reachable, these can be corrected by flexing the foot and pulling gently up into the birth canal. Care must be taken at this stage, as the thin wall of the uterus can be damaged. Epidurals and drugs to relax the uterus may be required to safely correct these.

Twisted uterus or uterine torsions can be a complication, requiring early identification and skilled manipulation to correct. These tend to occur during Stage 1 labour, with a classic history of ‘started to calve but stopped’. It is the live calf inside the uterus that causes the twist, we see higher numbers on some dairy farms, where milk fever/calcium deficiency may be a factor in extended Stage 1 labour causing foetal stress which may initiate the twist.

On examination of the cow, you can feel a twist or tight band in the floor of the vagina. You may or may not be able to feel a calf, depending on the degree of twist and how dilated the cervix is. The major blood supply to the uterus, placenta and the calf is included in the twist. Therefore, the duration and severity of the twist will determine the outcome.

All obstetric procedures are easier to perform if the cow is standing but delivering the calf in a crush is a high risk in case the cow goes down. Calving gates or haltered cows allow cows the space to lie down during delivery.

Caesarean sections are commonly needed if the calf is too big to prevent further risk of injury to the cow and calf. Nothing is more rewarding than a successful outcome. Caesareans are major abdominal surgery, performed very much in ‘field conditions’ and not without risk. The single biggest risk for a successful outcome for the cow is if the calf is already dead.

Farm facilities have generally improved, with good cattle crushes or simple calving gates to safely restrain the cow during surgery. Good clean facilities make a massive difference to the risk and ease of the procedure. Unfortunately, situations are still encountered where animals are not suitably restrained, with dirty surroundings, poor lighting and limited clean water.

Once a calf is safely delivered into a clean dry environment, it is vital the calf receives good quality and quantity of colostrum within the first six hours of life.

Post calving complications for the cow include tears and haemorrhage. Once the calf has been delivered, check for twin calves, vaginal tears and arterial bleeds, (large amounts of bright red blood) Uterine prolapses are common, risk factors include a long and difficult labour and delivery, recumbent post calving and calcium deficiency/milk fever – causing delayed contraction of the empty womb. Replacing prolapses early is key to recovery as haemorrhage and infection are common complications.

Calving cows should be a stress-free process, with cows calving without any assistance. Many problems can be avoided with good management, nutrition and bull selection. However, early identification of potential problems is important and knowing when and when not to intervene.

If in doubt, call a vet for advice as we like solving problems and love successful outcomes.