The main profit driver for sheep farmers is the kilograms of lamb weaned (and sold) per ewe mated. Once born, keeping lambs alive and getting them to thriving, is key to making this happen.
We can’t alter the weather and the impacts that has on survival and growth in their first few weeks, but from docking onwards, the power is largely in our hands.
A study completed recently found 23% of lamb deaths from docking until hogget lambing, could have been prevented by complete vaccination of lambs, started at docking1. Clostridial diseases are one of the most important and common diseases affecting sheep and they are easily controlled through effective vaccination. However, there are commonly gaps in the robustness of vaccination programmes which result in increased deaths - and less lambs to sell. Coupled with this, another study found that 13% of lambs don’t receive enough antibodies in colostrum, irrespective of litter size2. This means that hoping your lambs have enough antibodies on board to last until weaning is probably just that - hopeful!
Despite robust vaccination programmes, lambs can still die from clostridial disease. This may be because the challenge was extremely high and overwhelmed their immune response, or it could be caused by another bacteria, not in the standard 5in1 vaccine. Cl. sordellii is the next most commonly diagnosed cause of clostridial deaths in sheep3. It is more likely to occur when lambs are grazing high carbohydrate feeds, are rapidly moved from one feed type to another or if they are on root crops or new pastures. These conditions can lead to rapid changes in gut flora allowing for activation of spores and toxin production. In these instances, changing to Ultravac® 6in1 SD vaccine, which contains the antigen for Cl. sordellii, can help lessen the incidence of death.
Regardless of vaccine type, best practice involves vaccinating early (start at docking), repeating with a booster 4-6 weeks later, followed by an annual booster. Lambs should be vaccinated using clean, sharp (new) needles that are ¼ inch long and 18 gauge, given under the skin of the neck, to help prevent blemishes at slaughter. Animals should be healthy and dry when vaccination occurs. You can download our best practice vaccine timing and administration guides below for further information.
1 CM Bingham, A Hodge, Lamb mortality and clostridial deaths 2021 Proceedings of the Sheep and Beef Cattle Veterinarians and the Deer Veterinarians Branches of the NZVA
2 Sutherland, S. Colostrum intake by lambs on four commercial farms in the Wairarapa. Proceedings of the Society of the sheep and beef cattle veterinarians and the deer branch of the NZVA. 2019, 43-46.
3 Surveillance Magazines, MPI
Posted by Dr Victoria Chapman, Veterinary Adviser, Livestock.
Zoetis New Zealand Limited. Tel: 0800 963 847; www.zoetis.co.nz. ULTRAVAC is a registered trademark of Zoetis. ACVM No. A010191.