Duck meat is slowly becoming popular and more people are enjoying it as a meal. This is in contrast to a few years back when it was mostly only available in high-end restaurants.
Most people appreciate it for its rich flavour and juicy mouthfeel. It is a good source of protein and minerals, which include selenium and zinc – important for boosting the immune system.
More Smart Harvest readers have been inquiring about diseases that affect ducks. Domestic ducks are generally regarded as more robust and hardy compared to other bird species.
With the right diet, fresh water, room to exercise and a clean environment, ducks tend to get sick less often but farmers need to be aware of some diseases that may cause massive losses if they strike. Some of the common diseases include duck plague and duck hepatitis.
Duck viral enteritis/duck plague
This is an acute, highly contagious and fatal viral disease of ducks, geese and swans. It affects all ages of ducks although adults are more vulnerable. In ducklings, symptoms include greenish diarrhoea, dehydration and blue coloured bills (beak).
Blood stained vent area may sometimes be present. Sick adult birds show sluggishness, anorexia, weakness. They are scared of light (photophobia) and tremors may be exhibited.
In adult ducks, a drop in egg production and high mortality are some of the first signs. Dead birds usually have blood stained feathers around the vent and may show a bloody nostril discharge. Mortality may be as high as 100% and most birds that exhibit the clinical signs die within five days.
The virus is transmitted by infected birds in the flock or by contact with contaminated environment, especially contaminated water bodies. Wild ducks have been associated with disease outbreaks – they act as disease carriers. Avoiding contact between the wild waterfowl and domestic ducks is the best measure in preventing the spread of duck plague.
Standard bio-security measures should be employed to keep the disease at bay. Vaccination has been used effectively in control of outbreaks. Duck enteritis has no effective treatment.
Duck Virus Hepatitis (DVH)
This is one of the commonest diseases that affect ducklings under five weeks of age. It is a severe, acute viral disease that causes hepatitis in young ducks. It has a short incubation period and sudden onset, and mortality is usually very high.
The disease is found in all duck-raising areas in the world. Three different types of the disease have been documented.
In type one, signs appear 18-24 hours after infection and mortality of up to 90 per cent occurs in ducklings under the age of one week. Ducklings squat, have partially closed eyes and usually succumb within one hour from the onset of clinical signs. Dying ducklings have a characteristic paddling (spasmodic) kicking movement.
Type two clinical signs appear 1-4 days after infection and mortality may vary from 10-50 per cent. It is less severe than type one. Severely affected ducklings have convulsions.
Type three is less severe than the other two categories and mortality is also lower.
Prevention of duck hepatitis is achieved by strict isolation of ducklings, especially during the first five weeks of age. Rats act as reservoir of the virus and therefore pest control is paramount in controlling the disease.
The virus is quite stable in the environment and contaminated pens aid in the spread of the disease to young susceptible ones. The virus has been shown to survive for up to 10 weeks in contaminated brooders. Vaccines for each of the different types of the disease can be used to provide immunity to the birds. Farmers purchasing ducklings should ensure they source them from vaccinated breeders.
- The writer is a veterinary surgeon and runs Nature Kuku, a farm in Naivasha that produces kuku kienyeji breed and trains smallholder farmers.
tonykiragu@gmail.com
