Concerns rising costs may be impacting routine herd vaccinations on NI farms

VSSCo. Ltd have noticed a decline in the total number of doses of cattle vaccines sold throughout the first four months of this year – a reduction of 12 per cent on average across the four main vaccines for BVD, Infectious Bovine Rhinotracheitis (IBR), Leptospirosis and Salmonella – versus the same period last year.

VSSCo was established in 1956 as a veterinary wholesaler of pharmaceutical products and a distributor of veterinary equipment and consumables.

As farmers continue to be hit with extortionate bills, management at VSSCo have expressed concerns that some farmers may be opting to delay, or even miss, some of their routine herd vaccinations.

This could impact the profitability of their herd down the line, adding further to financial pressures.

The provisional results of the June 2021 Agricultural Census were released by DAERA in December and revealed cattle numbers had increased by four per cent to 1,681,991.

The number of beef cows increased by one per cent to 246,956, while the number of dairy cows increased by two per cent, to 318,372.

From January to April 2022, the amount of BVDv vaccine sold ex wholesaler was down 15 per cent versus the previous year, however, the amount of IBR vaccine sold was up three per cent, possibly because this vaccine is used in beef cattle, as well as in breeding herds, and beef cattle are very valuable at present.

The number of Leptospirosis vaccinations sold in the first four months of 2022 was down eight per cent ex wholesaler versus the same period in 2021, furthermore, sales of salmonella vaccines have decreased by 23.5 per cent in the first four months of this year versus last year.

There are two vaccines available for Leptospirosis, which is a common reproductive disease of cattle in the British Isles.

Acute leptospirosis is seen less frequently and usually presents as either an abortion outbreak or the birth of weakly calves, or classic milk drop syndrome in lactating dairy cows.

In contrast, the most frequent presentation of leptospirosis in cattle is a chronic, hidden infection resulting in reproductive failure due to embryonic death and failure to conceive.

The chronic silent form can cause huge losses at a herd level due to extended calving intervals in both dairy and suckler herds.

The organism is shed in the urine and animals at pasture are at risk if they have access to contaminated water.

The NI BVDv eradication programme has been ongoing for six years and, while good progress has been made in identifying and removing PI (persistently infected) calves, there are still herds where BVDv is active throughout the country.

This means that, while many herds will have been BVDv free for several years, there is still the risk of BVDv re-entering a herd, either due to the purchase of a pregnant animal or from over the hedge contact when animals are at pasture.

Latest figures from the BVD Programme show that, for the first time in the life of the NI BVD Programme, for three consecutive months fewer than 40 herds have been retaining BVD positives for more than five weeks.

Snapshot figures from the start of May indicated that there were 181 living BVD positives in 113 affected herds.

A spokesperson from Animal Health and Welfare NI explained: “The rolling herd level prevalence has fallen to 4.57 per cent, the lowest level seen this year, with a greater improvement being seen in beef herds compared to dairy herds.

“As the programme progresses and infection levels decrease, there is also a decrease in the levels of natural immunity to BVD in herds.

“This means that the likelihood of pregnant cattle being exposed to virus has decreased, but the susceptibility to infection may have increased because there is less natural exposure to the BVD virus.

“This reduction in immunity may leave herds more exposed to large outbreaks, should a PI animal be introduced.

“BVD vaccination induces a protective immunity in breeding animals to help avoid a range of negative outcomes of infection, including failure to conceive, abortion, birth defects and, most importantly, the creation of calves that are persistently infected with BVD virus.”

They continued: “The decision whether to vaccinate or not depends on the risk profile of the herd.

“Factors to consider in whether to vaccinate will include: animal movements into a herd, the level of contact with neighbouring herds, whether there have been outbreaks in a neighbouring or associated herd; a greater than normal throughput of people, such as on demonstration farms; and in herds of high genetic merit females where progeny is of a higher value.

“Decisions on the use of BVD vaccine, including when to stop a vaccination programme, are herd specific and should be taken by each farmer in discussion with their own veterinary practitioner.

“Stopping a BVD vaccination programme prematurely, where biosecurity risks still exist, could be a very expensive mistake.

“Cost savings need to be balanced with the risk of BVD recurring.”

Animal health plans should be discussed with the farm’s vet, and a full BVD investigation carried out if there has been previous infection in the herd.

Many different types of Salmonella can infect cattle and the clinical signs vary from abortion to bloody diarrhoea, joint ill and pneumonia.

The disease can manifest as acutely sick collapsed calves, which often die, or in chronic infections where some calves become progressively weaker and may go off their legs.

If in doubt consult your vet to help you diagnose the cause of the problem.

In addition, Salmonella is a zoonosis - animal disease which can spread to humans.

Good hygiene, particularly for newborn calves, along with adequate colostrum is vital, plus a herd vaccination program can help control two of the common strains of Salmonella found in cattle.

If you have had Salmonella on your farm in the past, and controlled it through the measures mentioned, allowing the Salmonella vaccination program to slip means the disease will re-appear, as many herds have chronic asymptomatic carriers.

IBR, meanwhile, is a highly contagious viral infection caused by Bovine Herpes Virus 1.

It affects the upper airways leading to a mucky discharge from the nose and eyes.

Affected animals will have a high temperature, be off form with reduced appetite, and will suffer a drop in milk production.

The disease is often seen in recently purchased beef cattle, which have come from multiple sources and hence vaccinating beef cattle for IBR as soon as possible after purchase is prudent.

As it is caused by a Herpes virus, animals that are infected will carry the virus for life and can start to shed it again under stress.

This is very important in dairy herds that are IBR positive, meaning that unless vaccination programs are kept up-to-date, the herd can experience flare ups of disease.

VSSCo staff are encouraging farmers who may have let their herd vaccination programs slip, to speak with their veterinary surgeon to create a plan to help maintain herd immunity, reducing the risk of disease outbreaks over the next year.