The number of sick animals on farms in NI requiring veterinary attention is less than in previous years, a leading private vet has claimed.

“I believe the BVD (Bovine Viral Diarrhoea) eradication programme is a big part of that. Removing infected animals means other animals are less prone to disease,” John Grant from Parklands Veterinary Group told farmers at a meeting in Cookstown last week.

However, he warned farmers not to get complacent, and until BVD is fully eradicated from the entire cattle population, farmers should remain cautious and continue to vaccinate for the disease.

Looking to the future, Grant believes that the role of a vet is gradually evolving from someone brought in to treat sick animals, to someone who will work alongside the farmer and a nutritionist to maximise health and production on the farm.

We must work on the principle of as little as possible, as much as necessary

A major issue driving that change is the threat of antimicrobial resistance in the human population, and the potential link to antibiotic use in farm animals – “forget Brexit, this is far more important”, suggested Grant.

He said that he didn’t ever want to end up in a position where he wasn’t allowed to sell antibiotics to his farm clients, but to avoid that, emphasised the importance of minimising usage on farms.

“We must work on the principle of as little as possible, as much as necessary,” he said.

Already pig farmers in the Red Tractor Assurance scheme are required to upload records of medicine use to a central site run by AHDB, and Grant believes it is only a matter of time before other livestock producers have to do something similar.

Frowned upon

On dairy farms, he said that blanket use of dry cow antibiotic tubes will be frowned upon, and all farmers will eventually have to milk-record their herds to identify the individual cows that require treatment, rather than just a teat sealant.

“Our vaccination programmes will have to get more robust. We will all have to up our skills. Bacteria and diseases don’t have their own feet – they arrive on animals, people, lorries, water, birds and rodents,” said Grant.

Critically important

A key element in avoiding antibiotic resistance is to limit the use of critically important antibiotics (CIA) in farm animals.

These are antibiotics that are also used in people, so if resistance developed in animals it would pose significant risks to human medicine.

We are using less CIAs – are we finding a huge drop-off in animal survival rates? The answer is no

Products such as Baytril and Marbocyl are included in the CIA list.

The advice to vets is only to use these products as a last resort. “We are using less CIAs – are we finding a huge drop-off in animal survival rates? The answer is no.

We can still produce healthy stock without these,” said Parklands vet Philip Abernethy.

He maintained that improved hygiene in the calf shed was a critical part of minimising antibiotic use on many farms, and in particular cryptosporidium is still the main cause of calf scour.

Given that it can persist in the environment, proper cleaning involves power hosing and application of a detergent. The house should then be allowed to dry before a disinfectant is used.

Room for improvement in calf housing across NI

Earlier this year, AFBI scientists working alongside CAFRE dairy advisers assessed calf housing on 66 farms across NI as part of a new project called Optihouse.

According to Aaron Brown, a PhD student at AFBI, the work highlighted a big variation in hygiene across the farms.

“In general, there is a lot of room for improvement,” he told farmers at the Parklands meeting in Cookstown.

While over one-third of farmers were regularly cleaning out and disinfecting calving pens, others were only cleaning out once or twice per year, and in some cases the same calving pens were also used for sick animals.

“On some of the farms, calves were dropping into a dirty environment. If problems are building up as the calving season progresses, you are not cleaning out properly,” he said.

Other issues found during the study included feeding equipment that was not clean, as well as dirt accumulated in water drinkers.

While some farmers were regularly washing out pens, they often forgot to clean out the drinkers.

Cryptosporidium can survive in water for up to six months, pointed out Brown. Only 3% of water samples were to the highest standard.

Good hygiene and ventilation is critically important in the calf shed, farmers were told

Brown also identified potential issues with how calf jackets are used. In up to one-third of cases, these jackets were not washed between calves, increasing the risk of disease spread.

On ventilation in calf housing, Brown emphasised the importance of having air inlet and outlet, so that calves have access to fresh air at all times. Over 50% of calf housing was not to the required standard for ventilation.

Changes

AFBI hopes to identify changes that can be made to existing housing to improve hygiene and ventilation, and develop blueprints for new modern houses.

Sucklers too fat at calving

Too many suckler farmers have their cows overfat at calving, and with good silage made this year, there is a risk that this problem will arise again in 2020, warned Parklands vet Eamon Donnelly.

“We saw some monster calves this spring, especially in cows that had been outside for a few weeks. A spring-calving cow should be in condition score 2.5 to 3, and you want it stabilised 50 days pre-calving,” he suggested.

A thin cow at calving increases the risk of low-quality colostrum

Where cows are thin, the condition score should be corrected early in the dry period. A thin cow at calving increases the risk of low-quality colostrum.

However, where cows are in good condition, and silage with an ME greater than 11 is being fed, it is important to restrict feeding. A dry cow mineral should also be fed up to two months pre-calving said Donnelly.

Deficiency

The main purpose of the dry cow mineral is to help avoid milk fever. However, many farms, especially in the mid-Ulster area, are deficient in selenium, and in particular, iodine.

This causes a number of issues such as weak calves that are slow to suckle.

“We recommend two boluses per year – one at turnout and one again at housing” said Donnelly.

He also reminded farmers that now is a good time to think about treating for fluke, especially given that the risk is moderate to high this year.

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