DIFFICULT calvings are one of the main challenges for any beef farmer and it is also a big threat to the profitability and efficiency of their business.

In an ideal world every cow and heifer would calve themselves, have a live calf with little or no intervention from the farmer or vet.

Unfortunately, this is not always the case, especially with heifers calving for the first time. A target for any beef herd should be <five percent dystocia. The primary cause of calving difficulties is a disproportionately large calf size compared to the pelvic area (birth canal) of the heifer/cow.

There are a number of key factors to consider for heifers to ensure that calving goes as smooth as possible. These are:

· Looking at EBV’s (estimated breeding values) of a bull for calving ease, gestation length etc

· Achieving at least 0.9kg DLWG (daily live weight gain) of replacement heifers so that they are 65% of mature bodyweight at serving and calving at approximately 2 years old

· Good BCS (body condition score) at calving. A good target is 3 for autumn calving and 2/2.5 for spring calving herds – over conditioning leads to less room for calving

· The use of a pelvimeter prior to breeding

Calf birthweight and size are primarily influenced by the choice of bull used. EBV’s (in particular calving ease) are widely used by beef farmers and they will be a major influence on which bull is used for heifers.

Also, if farmers are breeding their own replacements then maternal genetics have an important role to play.

However, a factor contributing to calving problems which we cannot determine by simply looking at heifers is the size of their pelvis.

Factors which influence the pelvic size of heifers include:

· Dam and sire genetics

· Breed

· Level of nutrition

A pelvimeter is a useful device which can be used to measure the internal area of a heifer’s pelvis. It takes two measurements – the horizontal width and the vertical height of the pelvis via the rectum. The figures are then multiplied together to obtain a total area in cm2. The area can then be compared to a known minimal internal area and there are specific values for specific breeds of a certain age.

The aim is to find heifers with abnormally shaped or small pelvic areas so that we can choose replacement heifers with the best chance of calving without assistance.

Paragon Veterinary Group is a Cumbrian-based veterinary practice with over 80 years experience in caring for animals. The name ‘par-a-gon’ refers to a model of excellence or perfection, and over the years we have gone from strength-to-strength to build up our reputation to the highest possible standards in our field.