Clostridial vaccines offering an add-on of pasteurella protection are currently experiencing supply issues for some pack sizes. There is still some supply in the market and increased supplies are in the pipeline and should be replenished in February onwards.

Supplies of the popular vaccine, Heptavac-P Plus, which offers protection against seven clostridial disease strains and pasteurella pneumonia, is affected.

There has been a number of queries from farmers in recent weeks asking if it is possible to select another vaccine for the booster treatment and if doing so will boost protection and immunity derived through passive transfer via colostrum.

The first port of call is to speak with your vet or supplier re vaccine availability as supplies may be available or possibly sourced elsewhere.

If that’s not a runner then a plan can be made on what the best solution for your farm may be.

Veterinary thinking

Veterinary advice on changing vaccine and boosting immunity appears to vary.

Some vets are advising farmers that selecting another vaccine that covers the same seven strains of clostridial diseases as Heptavac-P Plus will achieve a satisfactory boost in immunity required to deliver protection via colostrum.

Some have told farmers that they are unsure but with no other option available, due to timing, they are advising farmers, and particularly those with a history of issues, that they have nothing to lose in doing so.

Others are of the opinion that the different titre of antigens in different vaccines makes it difficult to predict if immunity will develop or if it will reliably boost. This is especially the case where a vaccine may be changed during the course of a primary course.

If sufficient time allows, some vets have encouraged farmers to administer a primary course of the alternate vaccine.

However, in many cases the timeframe is such that farmers are only realising there are supply issues when it is coming close to the time to deliver the annual booster vaccine.

Vaccines possessing pasteurella protection but a lower number of antigens to clostridial diseases are in general not recommended to be administered pre-lambing as they do not possess the suite of protection covered by others, with lamb dysentery the main concern.

These vaccines are aimed at sheep destined for slaughter and, if available, can be administered to lambs at a later date.

Table 1 covers the main vaccines and lists the clostridial diseases that protection is provided against and any notable features. The passive transfer derived via colostrum is directly influenced by lambs receiving sufficient colostrum.

The volume of ewe colostrum lambs should ideally receive is determined by their weight.

Management principles

The general recommendation is 50ml per kilo birthweight in the first feed and 200ml to 250ml per kilo liveweight in the first 24 hours of life.

Where colostrum is limited or in multiple births then it is important to try to ensure that each lamb receives some ewe colostrum if a top-up of a colostrum alternative is being used.

Implementing management practices can also help in reducing the risk of clostridial disease by minimising stressors that can trigger disease.

For example hygiene at assisted births and hygiene at lambing can be a trigger for lamb dysentery, pulpy kidney, tetanus, blackleg, malignant oedema, gas gangrene and clos. Sordelli infections.

Timing of administering the vaccine is also important and as can be seen in Table 1 differs between vaccines.

Handling of the vaccine is also critical and care should be taken to store and administer the vaccine as per manufacturer’s guidelines.