Whatever the market conditions for sheep, the returns will always be greater if the flock is healthy. Louise Hartley asks John Macfarlane for his advice on making sure vaccinations are stored properly and administered correctly.
Vaccines are one of the most important tools in maintaining a healthy and profitable flock and there are currently about 15 licensed vaccines in the UK for use in sheep.
Vaccines stimulate the body’s immune system to recognise, fight and remember a disease in case of future exposure. Some offer protection which will last for the productive life of the sheep, while others need more frequent, often annual, revaccination.
Northumberland-based vet, John Macfarlane, chairman of XLVets, says: “The chain of supply from manufacture to point of sale is highly regulated and subject to frequent inspection. At Alnorthumbria vets, we check and record all fridge temperatures daily and deliveries are received from refrigerated transport. Therefore, to ensure the vaccine will work properly on-farm, the same level of care should be taken between the point of sale and the animal - and often this does not happen.”
Mr Macfarlane says it is important to make sure the vaccines are correctly stored until used; typically, at 2degC to 8degC, normally away from light and avoiding freezing. If vaccines are supplied by post or carrier, make sure these conditions have also been maintained throughout transportation.
Perhaps the most important part of any vaccine is the package insert, says Mr Macfarlane.
“The package insert provides the facts on how to use vaccine properly, including diseases or organisms prevented, dosage, route of administration, interval between doses and revaccination interval. It also details storage conditions, shelf life after opening the bottle, suitability for use in breeding or young sheep and concurrent use with other medicines. There is important guidance on how to dispose of unused vaccine and empty containers and warnings in the event of accidental self-injection for the operator and for doctors. The consequences of accidental self-injection with some vaccines can be extremely serious so they should be administered very carefully.”
Always make sure you are familiar with the content of the package insert before you store, use or dispose of the vaccine or its container, advises Mr Macfarlane.
Sheep have a particularly efficient system of protecting their newborn lambs from infection for the first few weeks of life, known as passive transfer.
Vaccinating against pasteurellosis/ mannheimia and clostridial diseases, a few weeks before lambing will stimulate enhanced antibody protection by the ewe which is then concentrated in the colostrum.
“Antibodies from colostrum ingested in the first six hours provide protection for the first few weeks of life. Good quality colostrum is, for the lamb, the most valuable and economic medicine you will ever give to them,” says Mr Macfarlane.
“Animals which are ill or injured will respond poorly to any vaccine, so vaccination should be delayed until they are well again.”
For programmes which require double primary course vaccination or regular boosters, the failure of any dose is likely to leave the sheep susceptible for the remainder of its life.
Mr Macfarlane says: “If one booster is not done properly, subsequent boosters are unlikely to reinstate full protection. Therefore, it is crucial all vaccinations are done correctly with a vaccine which has been properly stored and prepared and with clean equipment which delivers the correct dose.”
A Special Import Certificate or a Special Treatment Certificate may be granted allowing vaccines available overseas to be imported for use in the UK, such as for control of campylobacter abortion.