Sheep farmers that use vaccines to prevent chlamydial and enzootic abortions are likely to encounter supply shortages in July and August.
Issues around supply are expected to materialise following technical problems within manufacturing plants, with some of these difficulties still to be resolved.
Veterinary practices across NI currently have a plentiful supply of products, such as Enzovax, in stock.
However, the expiry date for most of these products is the end of June.
The advice from local vets is that Enzovax will provide effective cover to breeding sheep throughout the entirety of the gestation period, regardless of the vaccine being administered in late June.
Manufacturers are hopeful that supply chains will return to normal in late summer to early autumn.
Sheep management: enzootic abortion, selling hoggets and scheme dates