Do calves need an IBR vaccine?

Turning calves out to grass for the first time is seriously rewarding. Rearing healthy calves in the first place takes great effort and hard work.

Minimising the impact of diseases like diarrhea and pneumonia can be challenging and this year was no exception. Weaning dairy calves, dealing with coccidiosis threats, pneumonia and clostridial vaccination; the calf ‘to do’ list can be comprehensive. What about IBR vaccination?

IBR – Infectious Bovine Rhinotracheitis

Infection with IBR virus is widespread in the cattle population in Ireland, with evidence of exposure in over 70% of herds (both beef and dairy).  It is capable of causing disease (both clinical and subclinical) resulting in huge economic losses at farm level through lack of production and treatment costs.

The majority of infections are seen in cattle greater than six months of age, however all ages are at risk of IBR.

Clinical infections usually occur when animals are infected for the first time. Signs such as discharge from the eyes and nose, loud laboured breathing, high temperatures, resulting depression and reduced appetite may be experienced. Milk yield may be affected, and abortion may also occur.

Subclinical infections are those without overt clinical signs and for this reason may go unnoticed for some time in a herd. Subclinical IBR can result in losses of 2.6kg of milk/cow/day.

Those infected for the first time shed high levels of the virus for approximately two weeks. At times of stress (e.g. mixing/housing/breeding/calving) the virus can reactivate, and that animal may shed again. Every time an animal sheds the virus it has the potential to infect more herd mates.

Control of IBR

There are 3 components to controlling this endemic disease:

  1. Vaccination
  2. Biosecurity
  3. Culling

Vaccination

For effective control of IBR, vaccination must:

  • Reduce the number of new infections – Main cause of virus spreading in a herd
  • Reduce severity of clinical signs – Limit cost of disease impact

The time to start vaccination depends on the particular epidemiological situation of each farm. In the absence of virus circulation among the young calf group, vaccination is started at the age of three months, revaccination six months later and all subsequent revaccinations within six to 12 month periods.

This will provide protection against IBR virus and minimise the number of animals that become carriers. Herds that have a moderate to high seroprevalence of IBR, are high-risk and/or have clinical signs are best to remain on a six monthly vaccination programme until IBR is under better control in the herd.

If vaccination needs to be carried out before the age of three months (high prevalence/high-risk herds/disease in calves) then intranasal vaccination is the recommended route in order to overcome maternally derived antibodies.

An intramuscular vaccination programme then commences at three-four months of age, as stated above. For the spring calving herd this will mean calves will receive their first dose of a live IBR vaccine in June/July 2021.

Bovilis IBR Marker live

Bovilis IBR marker live provides protection by reducing clinical signs and virus excretion. It is the only single dose IBR marker vaccine for use either intranasally or intramuscularly. It is a 2ml dose with a fast onset of immunity (four days after intranasal administration and 14 days after intramuscular administration).

Biosecurity

Biosecurity can be further divided into bio exclusion and bio-containment.

Bio exclusion (the process of keeping disease out of a herd) is of particular importance in Ireland as many herds purchase cattle (e.g. the stock bull), avail of contract rearing for heifers, attend marts or shows (present Covid-19 restrictions excluded).

IBR can cross distances of up to five metres so neighbouring cattle during the grazing season can also be a source of infection, or vice versa.

Bio containment (the process of reducing the threat of infection within a herd) relies mainly on herd management strategies such as segregating age groups and indeed vaccination.

Culling

Culling of animals which have tested positive for IBR is a quick method to reduce herd prevalence. However, in many herds it is not a practical option as there are simply too many animals which are positive (once infected an animal becomes a life-long carrier) and therefore it would not be economically viable.

In summary, the majority of herds in Ireland are of medium or high seroprevalence so vaccination with a live IBR marker vaccine combined with biosecurity are the most practical and appropriate control methods. Many herds are missing a trick by only vaccinating the cows.

This is controlling clinical signs and the impact of IBR on production but not necessarily reducing the spread (to unvaccinated younger cattle) and therefore the number of new infections each year.

The aim of whole herd vaccination is to reduce the level of IBR in the herd over time. In answer to the opening question – yes; to IBR vaccination of calves.

2020 Virtual Farmers Journal Dairy Day

This year, the Farmers Journal #DairyDay will be held virtually on Tuesday the 24th of November. The virtual event is divided into three different sessions which can be viewed for free at here

2020 Dairy Day

As we move into the winter months, it’s a great time to reassess the herds winter vaccination plans prior to calving next spring. MSD Animal Health advise that a month pre-calving is a good time to give a booster shot of Bovilis IBR Marker Live.

The Bovilis IBR Marker Live 12-month vaccine protocol. Consult with your vet to access if this protocol is suitable for your herd.

Also, the time for scour vaccination is soon approaching. Remember, vaccinate cows & heifers 12 to 3 weeks prior to calving to provide passive protection to calves through colostrum feeding against three common causes of scour. For more information on winter vaccination, talk to your vet.

See some of our product and disease brochures below. If you have any questions, please contact your local vet to discuss in more detail.

Bovilis IBR Marker Live Download
Total Calf Health-Solutions Download
Bovilis INtranasal RSP LiveDownload
Leptavoid-HDownload
Bovivac-SDownload
Bovilis BVDDownload
Recharge the batteries – 60 day dry periodDownload

Virtual Tour: Is Your Shed Ready For Housing?

See below, a virtual tour of a Teagasc shed. On the tour, we draw your attention to different areas which ensure optimal living conditions for the animals.


Bedding & Animal Space

When housing cattle, it is important to allow enough space for each animal to feed, drink and rest stress free. Animals of various sizes will have different space requirements. Always ensure that there is adequate bedding of clean, dry straw available during the housing period. Sheds should be bedded regularly to keep moisture levels low. To check, kneel in bedding for approximately 1 minute. If your knees are wet, the shed needs to be freshly bedded. The objective of bedding is to keep the animal clean and dry. Space requirement varies depending on shed type and the animal type. A suckler cow on straw will typically need 4 to 5 m2 of bedding space and weanlings on slats will need between 2 to 2.5 m2. For further information accommodation requirements see figure 1.

Figure 1: Winter accommodation for beef animals

Feed Space

When housing cattle this autumn, it is important that all bedding from the previous year has been removed and the shed has been thoroughly cleaned. All areas of the shed including the feeding area should be power washed and adequately disinfected from the previous year. Feed space requirements depend on the feed availability. A general rule of thumb is to ensure each animal can feed at the same time. Typically, a suckler cow requires a feed space of 600 mm with space for two cows to pass behind. Diagonal barriers have the advantage of less bullying and reduce the amount of feed taken into the pen. Allow for the bottom rail when deciding the height of the stub wall. The animal’s neck should not normally come in contact with the top rail with diagonal feed barriers. See figure 2 below for further animal space requirements.

Figure 2: Winter accommodation for beef animals

Ventilation

The objective of shed design is to ensure adequate air flow on a still day and to shelter animals on a day of high wind speeds. While this is possible for newly built sheds, older sheds may not be able to provide this function and rely on the stack effect. The stack effect is where the heat generated by animals in the building rises and is replaced by fresh air coming in at a lower level of the shed (above the wall, under the eaves or through the side sheeting/boarding). See figure 3 which illustrates this process.

Figure 3
Ventilation Calculations – Inlets and Outlets

The rate of ventilation is influenced by the size of the openings, the roof pitch and the difference between inlets and outlets. As a general rule of thumb, the inlet should be at least twice the size of the outlet. When designing a new building or improving an old one, it is important to calculate the area of outlet required in a roof to allow heat and moisture from the livestock to escape by natural convection. If making improvements to shed ventilation, inlet and outlet areas should be at least brought up to the sizes outlined in the DAFM specification S101. When considering inlet sheeting/boarding it is important to look at the function of each option. In certain situations either due to the layout or situation of a farm building, natural ventilation might be inadequate. In this instance, mechanical ventilation could be considered. You should consult with your agricultural consultant for the best advice on which sheeting/boarding to use which will depend on the prevailing wind direction, type of animal and number of animals to be housed in the shed.

Outlets
  • Ensure the outlet area is clean and clear.
  • General required outlet sizes can be seen in figure 4. These figures can be modified based on stocking densities and roof pitch.
Figure 4
Inlets
  • Inlets should be provided beneath eaves using either a continuous opening, louvered sheeting, plastic mesh, or space boarding.
  • The inlet area should be at twice the size of the outlet area to create a natural air flow.

Water Access

Clean water access is a primary requirement of all animal housing and must be available at all times. It is important that the location and height of the trough can accommodate all animals in that shed. Water is frequently spilt around water feeders. Ensure that the area around the feeder is well drained and any spilt water can drain away from the bedding area. Avoid placing feeders in areas where spilt water will pool creating flooded areas of the shed. Aim to give access to 10% of the group to drink at any one time. Animal water intake depends on the age and stage of lactation. See figure 5 for more detail

Figure 5

For further information regarding sheds modifications talk to you vet, your agricultural consultant or visit the Teagasc webpage through the link here.

Source:

  1. Ryan, T. & Lenehan, JJ. 2016 – Winter accommodation for beef animals Teagasc beef manual
  2. Anon 2013. – Calf house ventilation – The basics MSD Animal Health

FAQ on IBR Control

Vaccination Starts With The Calf

There are 3 components to controlling this disease
1. Biosecurity
2. Culling
3. Vaccination

Biosecurity:
To keep the disease out of IBR free herds and to limit the spread in herds with IBR positive animals

Culling:
Culling of animals which have tested positive for IBR. In many herds it is not a practical option as there are simply too many animals which are positive (once infected an animal becomes a life-long carrier) and therefore it would not be economically viable.

IBR calf vaccination
Calves from 3 months of age can be vaccinated using Bovilis IBR Marker Live into the muscle

Vaccination
For effective control of IBR, vaccination must:
• Reduce the number of new infections – main cause of virus spreading in a herd
• Reduce severity of clinical signs – Limit cost of disease impact

FAQ on IBR disease and Bovilis IBR Marker Live


Do I need to vaccinate my herd for IBR?

75% of herds have been exposed to IBR, it is an endemic disease in Ireland. Clinical signs are not always present in infected cattle. Subclinical disease (without signs) can result in losses of 2.6kg of milk/cow/day. Speak to your vet regarding screening for the virus through bulk milk tank testing and blood sampling animals in your herd.

Herd level prevalence of IBR by county in Ireland1

I vaccinate my cows and heifers against IBR – should I vaccinate my calves?

The benefit from whole herd IBR vaccination starting with the youngstock is that the calves are protected from the virus and this minimises the number of animals that become carriers. Every animal that is infected with IBR becomes a lifelong (latent) carrier and these animals are the source of infection in the herd.

I vaccinate every 6 months against IBR – can I move to every 12 months now?

12 monthly vaccination (after the initial 2 vaccinations 6 months apart) may be suitable for low prevalence IBR herds. Speak to your vet on how to assess and monitor herd prevalence. Check out the below video showing how to get your herd onto the 12 month vaccination protocol for Bovilis IBR Marker Live. Again, consult with your vet to determine if your herd is suitable to move to the 12 month protocol

I got a high IBR reading in my bulk tank – what should I do?

Talk to your vet about what this high reading may mean in terms of virus in your herd. A high reading indicates that virus is actively circulating in the milking cow herd.

My bulk milk tank test is negative for IBR – does this mean my herd is IBR free?

Not necessarily; bulk tank antibody tests only detect IBR virus when at least 20% of the milking cows are carriers. If you have a suspicion that IBR is in your herd, speak to your vet regarding blood sampling individual animals.

I know IBR is circulating within my cow herd, can they pass the virus to the calves?

In short, yes they can. Cows are most likely to shed virus at times of stress e.g calving time, peak lactation. If calves are in the same air space (remember IBR can travel for 5 metres) as older animals who are shedding virus then they are vulnerable to the disease.

Sub-clinical IBR can have a significant impact on production output

My neighbouring farmer vaccinates for IBR – I’m a beef farmer, how do I check if my herd has IBR?

Blood sampling is the most common method to determine the prevalence of IBR disease within a beef herd. This involves sampling all animals or a representative number of animals in the herd. Talk to your vet for more information.

There is an outbreak of IBR on my farm – is it safe to use Bovilis IBR Marker Live in the face of an outbreak?

Yes, for the fastest onset of activity; 4 days, it can be given intranasally. Onset of immunity after intramuscular administration is 14 days.

I vaccinated my calves up the nose at 1 month of age against IBR – do I give them a booster?

Yes. Calves that received an initial shot of Bovilis IBR Marker Live up the nose will require a booster 2 ml shot, at 3-4 months of age. At this age or older animals, can be vaccinated either intranasally or into the muscle.

What is a marker vaccine?

Marker vaccines do not contain glycoprotein E (gE) and therefore do not cause production of antibodies to gE. Field virus and non-marker vaccines on the other hand do contain gE and therefore lead to production of antibodies to gE. An IBR gE ELISA test in herds that are vaccinating with marker vaccines allows differentiation between vaccine and wild virus antibodies. Non-marker vaccines are still available in Northern Ireland. IBR marker vaccines are the only type of IBR vaccine available in the Republic of Ireland.

Bovilis IBR Marker Live is the number 1 IBR vaccine in Ireland

Which vaccine should I use for IBR protection – live or inactivated?

Less shedding of the virus occurs in animals that have been vaccinated with a live vaccine compared to animals that had received inactivated vaccines. Studies have shown that live IBR marker vaccines provide better protection against clinical signs than inactivated vaccines. There is limited evidence that using inactivated vaccine can result in a better reduction of shedding by reactivated latently infected animals than live vaccine. Bulls intended for use as future AI sires must not be vaccinated with any type of IBR vaccine.

Addition info

Live vaccineInactivated vaccine
Primary courseStandard or low-risk herds
Young calves (2weeks-3months of age)Pedigree herds (except potential AI sires)
All herds including high-risk herds 
High prevalence herds 
In the face of an outbreak 
Comparison of live and inactivated IBR vaccines

Risk factors to a herd:

  • Purchasing stock (especially without a quarantine procedure)
  • Mixing stock from two different farms, including contract rearing operations
  • Poor boundary fences, IBR can spread for up to five metres
  • Bringing cattle to and from the mart
  • Attending agricultural shows
  • Personnel -Farm workers who are in contact with other stock

Talk to your vet today about IBR calf vaccination from 3 months of age, using Bovilis IBR Marker Live. For more check out our brochure here, our IBR page or Twitter page


References
1. Bosch et al (1996) An attenuated bovine herpesvirus 1 vaccine induces better protection than two inactivated marker vaccines. Veterinary Microbiology 52, 223-234