How beef farmer overcame BVD outbreak and high calf losses

When bovine viral diarrhoea (BVD) struck at the worst possible time at Rob Harris’s beef unit near Ludlow during mating, it caused a storm of late abortions and high calf mortality.

In fact, the outbreak, which hit his autumn-calving herd in 2018, left just seven live calves from 42 cows mated.

BVD was later confirmed at calving after a stillborn was submitted to the Animal Health and Veterinary Laboratories Agency (AHVLA) in Shrewsbury for post-mortem.

See also: More than 30% of English cattle herd join BVDFree scheme

As well as the huge financial loss suffered, Mr Harris, who farms at Rosebank Farm in Orleton, near Ludlow, Shropshire, says he considered giving up beef farming completely.

“When you’re pulling so many dead calves you lose confidence in the job. You wonder if it’s worth it,” he admits.

But, three years on, Mr Harris is glad he dealt with the situation promptly and decided to stick with beef. Although it meant a huge financial hit in the first year, owing to the number of dead calves and culling of persistently infected (PI) calves, the herd weaned 103% last season.

Infection

Although they still don’t know where the infection came from, vet Linda Morgan from Marches Veterinary Group, says the disease struck in the summer when the herd, which was unvaccinated and must have been naive at the time, was in the first three months of gestation.

From left: Linda Morgan, Rob Harris and Richard Taylor © MAG/Rhian Price

During this period, surviving embryos are transiently infected and will then become PI, meaning they produce high levels of the virus and can transmit the disease to other animals throughout their lives.

Determined to stamp out the disease quickly, Mr Harris worked closely with his vet, Richard Taylor, also from Marches Vets, to eradicate BVD.

This involved:

• Carrying out a hunt for PIs in the autumn-calving herd. No PI cows were detected, but five PI calves were found. These were separated and culled
• Mating was then delayed to enable the whole herd to be vaccinated against BVD
• The spring-calving herd (15 cows) was also tested and vaccinated. Testing was partially subsidised through BVDFree England
• Farm boundaries were double-fenced to prevent nose-to-nose contact with neighbouring cattle
• The breeding herd is no longer grazed in fields adjacent to neighbouring stock
• All calves were tagged and tested at birth last year to monitor for disease and any youngstock (including bulls) continue to be vaccinated before breeding. The older animals receive annual boosters.

System changes to help BVD control

For simplicity, Mr Harris has rolled the autumn block into the spring so that all 65 heifers and cows can be vaccinated at the same time during the first week of May, approximately one month before mating.

“Heifers need to be vaccinated three weeks before mating and cows need an annual booster. If you can simplify it and have one protocol for all stock, it limits mistakes,” says Mr Taylor.

At the time of the outbreak, Mr Harris was buying about 100 store cattle a year to finish, but he put an end to this practice in January 2020 in favour of finishing 200 store cattle annually on contract for Dunbia.

“I decided that if I was going to stick with cows, I needed to make it as safe as possible,” he explains.

The animals arrive having been tagged and tested for BVD and are kept indoors in a separate shed, so they pose a very low risk to the suckler herd.

Herd performance benefits

The improvements to herd health in such a short period have been exceptional.

“Last year, 100% [of the herd] that went to the bull scanned in calf,” says Mr Harris. Altogether, 55 cows reared 57 calves last season, including two sets of twins.

Medicine purchased to treat pneumonia cases reduced by 84% in 2020 in comparison with 2019.  

Furthermore, no calves have had to be treated for pneumonia this year.

“It’s amazing how well the herd is performing post-vaccination. I nearly forget how bad it was sometimes,” says Mr Harris. 

The herd is now officially BVD-free, with a cohort of home-bred bulls and heifers blood-tested annually between 9-12 months of age to check for antibodies and confirm herd status prior to being vaccinated.

“You can’t do them any earlier because there are still antibodies [in their system] from the colostrum,” Mrs Morgan explains.

Mr Harris’s biggest regret is that he didn’t vaccinate his herd sooner.

“I never want to go through that again. It was awful,” says Mr Harris, whose one piece of advice to other farmers not already vaccinating their herds is to start now.

Mrs Morgan says BVD infection can be particularly problematic for block-calving herds with a tight calving pattern, because when disease strikes all the cows are at the same stage of gestation. This can result in PI calves, as well as an abortion storm.

“Most farms had BVD endemically, but now we have BVD initiatives, many herds are naive, and if they are unvaccinated, they are at high risk of getting the disease,” she explains.

She says farmers need to be more aware of their own herd’s disease status, as well as the disease status of animals they are buying in, and isolate and test these incoming cattle, as they could be a reservoir of infection.