Vet Viewpoint: Flies, BVD, calf hypothermia and dairy genomics

Tackling nuisance flies, hypothermia in young calves and BVD are the main talking points among XL Vet across the UK.

One vet also takes a look at genomics to consider their use and the decision making process faced by dairy cow breeders.

See also: Fly control in cattle: the options compared

Chris Just

Chris Just

St Boniface Veterinary Clinic, Crediton, Devon

As the summer weather warms up we are seeing the inevitable emergence of flies in greater numbers.

This year we are experimenting with controlled release of parasitic wasps to tackle the problem.

The tiny wasps are not, thankfully, interested in people or animals but lay their eggs in the pupae of nuisance flies.

As well as the benefits to animal health the move helps to improve the working environment for farm staff.

That is a major positive when you consider the contribution a contented workforce can make to a successful business.

It also fits with the longer-term aim to use fewer chemicals around the animals and the food they produce.

With widespread success in reducing antibiotic use in UK livestock it won’t be long before we will throw the gauntlet down to further reduce other chemicals around food production too.

Catarina Neves Mendes

Catarina Neves-Mendes

Dunmuir Veterinary Group, Castle Douglas, Dumfries and Galloway

It is common to come across prostrate 0-7 day-old calves. They’re usually ‘soft’, ‘not keen’ and ‘lazy’ but will eventually pick up.

But for some this is not the case and in an hour, they can become severely debilitated.

It is important that farmers are able to recognise this situation and act on it.

Calves left in a cold and wet environment can develop hypothermia, and will eventually die.

It is important to check their temperature (≈39.2C) regularly and decide when it is time to call the vet.

When a calf’s temperature falls below 37C and heart rate drops below 90 beats/minute, emergency measures should be taken.

Taking the calf to a vet clinic increases its chance of surviving: it can be overseen in a controlled temperature environment, given intravenous fluid therapy and feed, and stimulation to stand up.

These are all crucial factors that can sometimes be difficult to achieve on farm.

Simon Wilson

Simon Wilson

Cain Farm Vets, Llansantffraid, Powys

We have recently held our BVD Free England meeting and completed most of our first on farm meetings and youngstock screens.

As expected we have had a mixture of farms showing freedom from BVD and, sadly, some infected herds.

After each farm’s results have come in we have discussed a way forward, a common theme to all these meetings is the need to vaccinate breeding cows against BVD to prevent new carriers being produced.

These discussions also show that almost all farms in our area, purchase some animals.

Incoming cattle are a key way for BVD to enter a herd and so the need to isolate and test these animals prior to, or on arrival, is of vital importance to prevent the incursion of BVD into a herd and to avoid the costly consequences.

David Preece

David Preece

Tyndale Vets, Dursley, Gloucestershire

There doesn’t seem to be a dairy farmer left without a view on genomic tests and bull selection.

Do you select the bull with high type figures, the one with all the production, or do you just look at PLI?

Once the bull is selected the next question is which dams are selected to produce the next generation?

Here, again, opinion seems divided. Heifers are theoretically the best future dams as they are by the latest bull.

However, what if this bull wasn’t as good as the herd, what if her dam was poor? What about the best older and proven cow?

Opinion on farm varies between all these and is a minefield of decision. Maybe the time has come to let the genomics and PLI figures do all the decisions for the dairy cows?