If you keep a calendar with key farm management dates, 'vaccinate stock' could be a key entry at this time of year.
But why, it's an annual vaccination after all, isn't it?
Firstly, with abundant spring growth, losses due to enterotoxaemia, also known as pulpy kidney, become a distinct possibility.
Second, a feature of the enterotoxaemia vaccine is the duration of immunity it provides may be quite short. It may only give three or four months of protection.
Therefore, a booster dose should be given before a high-risk period, i.e. before the beginning of spring.
Young stock in good condition, up to two years of age, are most affected by enterotoxaemia; however, deaths in older stock may also occur.
Enterotoxaemia is caused by a toxin produced by Clostridium bacteria, which is found in the bowel of normal, healthy cattle and sheep.
Enterotoxaemia occurs when a large amount of readily fermentable feed is present in the gut, leading to the rapid multiplication of bacteria and a lethal level of toxin production.
Due to the rapid progression of the disease, an animal affected by enterotoxaemia will typically be found dead in the paddock. On post-mortem, rapid decomposition of the carcass is seen.
Little can be done to treat an animal affected by enterotoxaemia; therefore, the emphasis should be on prevention.
The key to prevention is to ensure all livestock are adequately protected through vaccination.
As with any vaccination program, adult cows and ewes should be vaccinated about one month before giving birth to give their calves and lambs maternal or passive immunity through colostrum.
Passive immunity typically lasts about six weeks; after this period, calves and lambs require vaccination to gain active immunity. This is achieved by giving two injections at least four weeks apart.
Hopefully, all producers will benefit from the upcoming spring conditions without being troubled by the problems they may bring.
For further advice, please contact your local veterinarian, Agriculture Victoria veterinary or animal health officer.
