Livestock producers in the UK face a range of common endemic and the occasional exotic disease danger. Commonly these can include clostridial diseases caused by ubiquitous soil dwelling bacteria that are always present as well as respiratory diseases like pneumonia/pleurisy posing a constant threat to the farm animal population.
Close to 4% of sheep carcases and nearly 6% of cattle carcases slaughtered in England alone in 2017 showed evidence of pneumonia/pleurisy which demonstrates how large the challenge is (Source; AHDB).
Pneumonia in cattle and Pasteurella in lambs pose a significant risk of death. Cattle with infected lungs have a reduced daily liveweight gain, lower carcase weight and poorer carcase classification at slaughter than cattle with healthy lungs (Source; AHDB).
Prevention of Pasteurella in lambs and Infectious Bovine Rhinotracheitis (IBR) and Bovine Respiratory Syncytial Virus (BRSV) in cattle should be a farm health plan consideration. Other factors such as adequate ventilation in building design and good nutrition and individual farm health history etc. should also be factored in. Ways of alleviating the disease risk burden is key especially in intensive units.
In the pig sector with 40% of the national herd outdoors there are equal challenges to endemic disease including Porcine Parvovirus (PPV). Poultry in the UK now accounts for half of all meat consumption as well as 12 billion eggs consumed annually and the challenge there is to protect the huge flock from a constant threat of infection from diseases such as Salmonella and Coccidiosis (Source; NOAH).
Vaccination of UK farm livestock therefore plays an essential role in protecting the welfare of farm animals by preventing or reducing disease. This reduces the pain and suffering often associated with illness and ensures safe and affordable food production. Vaccination can also reduce the reliance and usage of antibiotics and the danger of resistance build-up and where possible increase the natural immunity in our animal populations.
Vaccines work by stimulating the animal’s own immune system which responds and then can ‘remember’ should a real disease threat occur in the future. The use of vaccination for animal health therefore does not present a risk to the food we produce and consume.
Some vaccines if administered to pregnant livestock such as sows or ewes also offer protection to both unborn or newborn piglets. New lambs receive maternal antibodies from colostrum they consume in the first 48 hours after birth protecting the lamb for 6 to 10 weeks before their immune system develops fully.
Vaccination can also play a key part in eliminating certain diseases altogether and a good example is the Bovine Viral Diarrhoea (BVD) eradication programme in cattle where vaccination of breeding stock on farm prevents the creation of Persistently Infected offspring (PI’s) in the first 120 of pregnancy inutero. These PI’s if born alive are the main source of infection or re-infection within a herd.
Many vaccines are administered subcutaneously (under the skin) and the correct technique and injection site need to be adhered to as well as the correct vaccination equipment used.
Vaccine efficacy is maximised, and the risk of adverse reaction is lessened if the correct technique is used.
Choosing the correct vaccination site reduces the risk of hitting bone, ear cartilage, glands and damaging valuable meat cuts on the side of the neck, particularly in sheep with vaccination approximately 5cm from the base of the ear recommended.
Injecting at 45 degrees to the skin is most likely to successfully deliver the vaccine under the skin
Choice of the correct needle is important and a shorter needle than injecting intramuscular should be chosen. This is also dependent on wool cover in sheep and an 18-gauge needle 6mm but not exceeding 15mm in length is recommended