With lamb prices trending well ahead of last year and 78p per kg above the five year average1, UK sheep producers are being encouraged to protect valuable young lambs from preventable disease threats this spring.
“It’s important to remember that lambs are born with no antibodies to give them protection to ubiquitous disease threats and therefore rely in early life on passive transfer of immunity from the ewe in her colostrum – but this must take place within the first few hours of life. This passive immunity then starts to wear off after three weeks, leaving many lambs vulnerable to a variety of infections,” explains MSD Animal Health livestock veterinary adviser Dr Kat Baxter-Smith.
Unnecessary losses from clostridial diseases, such as pulpy kidney or from pastereurellosis, are a particular cause for concern with young lambs during the spring and early summer. According to data from Farm Post Mortems Limited, there’s often a large peak of pulpy kidney in the spring when lambs aged between two and eight weeks of age are affected2. On further investigation, in almost all the cases, neither the dams nor their offspring have been protected by vaccination.
Dr Baxter-Smith says that it is impossible to control the multiple and varied stress-related ‘trigger’ factors (e.g. a sudden change in the weather, alteration in diet or parasite infection) for clostridial diseases and other common infections, such as pasteurellosis, so vaccination of young lambs from three weeks of age is strongly advised.
She points out that coccidiosis is another key disease in lambs that is often triggered by stressful events. This is because any maternally derived immunity (gained from ewe colostrum) to this particular infection is known to wane at four to six weeks of age.
“After this, young lambs become particularly susceptible to the Eimeria parasite oocysts, which, once consumed from the environment, hatch and then invade the intestinal wall. This can then cause diarrhoea, weight loss and slow growth rates.
“Oocysts are ingested when lambs lick contaminated objects or ingest feed or water contaminated with faeces. If coccidiosis has been diagnosed, ask your animal health product supplier about the strategic use of an easy-to-administer, single oral drench alongside sound hygiene practices, which will allow some immunity to develop in your lambs without loss of performance or disease,” she advises.
On sheep units with a history of orf, Dr Baxter-Smith says that young lambs should always be protected from this parapox virus.
“Orf-affected lambs have been shown to be 2.2kg lighter on average at finishing, than disease-free animals1. There’s also an 82 percent chance that the mother of a lamb with orf will have the disease on her teats1, so failing to vaccinate lambs at the earliest opportunity could be costly.”
“Orf is also a zoonotic virus that can infect humans to cause painful sores on the skin. Consequently, it’s well worth discussing a flock vaccination protocol