Salmonellosis in your flocks is a threat to you and your customers. Salmonellosis is a disease of both humans and animals caused by a bacteria called salmonella. It is also commonly referred to as ‘infectious’ which means that the disease can easily be spread from one sick animal or human being to another. But why should a poultry farmer be concerned with this disease? The disease level of a poultry flock may determine the profitability of an operation or the general health of a household in close contact with the flock. Salmonella infections are associated with diarrhoea and systemic malaise and general body weaknesses in human beings. Infected animals or human beings may shed large number of organisms in faeces resulting into contamination of the environment. Infections in food animals like chickens often leads to contamination of eggs, meat and sausages. This makes Salmonellosis one of the most common and economically important food-borne zoonotic diseases in human beings. It is widely associated with intensively reared animals like pigs and poultry. This disease affects all species of animals and is more common in young animals and if not treated may result into death.
The most common signs are related with digestive tract but can show a wide range of clinical signs, like septicaemia, abortion, arthritis and diarrhoea. Infected poultry may not show any clinical illness but plays a major role as a carrier. The affected poultry then becomes important in the spread of infection between flocks and herds and as sources of food contamination and human infections. Infected young chicks will show anorexia, depression, ruffled feathers and will be seen huddling together. You may also observe somnolence (a feeling of wanting to sleep), dehydration, some will discharge whitish diarrhoea with pasted vents. If not treated, mortality may reach ten per cent.
Your vet can take individual samples for bacteriological analysis during acute stage of the disease. Such samples include, faeces, litter, dust, liver tissues and blood. Farmers are advised to avoid medication without disease presence confirmation by a competent laboratory.
The fact that this disease can jump from chickens to human beings, has a direct impact on health and well-being of workers and poultry consumers. It will result into illnesses and hospitalisation following consumption of contaminated fresh fruits, raw or undercooked eggs or egg products, including poultry meat.
You must start with a negative flock. Please note that this disease can be passed from one mother hen to day-old chick at hatch. To be on the safe side, buy your chicks from Salmonella- free hatcheries. Biosecurity is a key pillar in securing your farm from infection or contamination from other flocks or herd of animals. Practice an All-in, All-out programme- this essentially means keeping only one batch of flocks of the same age in the farm. Do not keep pigs and other animals where the chickens are. Restrict unnecessary visits into your poultry shed. Avoid sharing fibre egg trays from unknown source. Hygiene standards must be well maintained. Do not introduce backyard flocks into your compound and ensure you have a good rodent control programme. Remember that antibiotic treatment is only temporary, to reduce mortality and clinical signs, infected flocks should be culled.
There are killed and live salmonella vaccines available in the market. Consult your veterinarian on best vaccine for your local area. I do however recommend 2 vaccinations of long-living birds at six to eight weeks of age and another shot at 14 weeks of age both administered intramuscularly. These vaccines are safe and efficient in reducing mortality and drop in egg production. They also reduce hen to egg transmission. However, vaccination must be supported with good hygiene practices, rodent control, restricted flock visits and keeping away backyard flocks.
[The writer is Head Vet at Kenchic, [email protected]]