FLHS Causes Loss of Half Laying Flock16 August 2010
BHUTAN - A farmer is awaiting a report on what caused the death of half his laying flock. Fatty liver haemorrhagic syndrome (FLHS) is suspected.
A poultry owner is Trashigang is awaiting news of what actually killed 386 hens of 720 in his poultry farm between 27 April and 29 May this year, reports Kuensel Online.
"Not a single hen died in the first three months of the year," said the farm manager, Chandra Bahadur Thapa. Then, on 27 April, 35 hens died. It is the highest number of deaths in the farm since it was established in September 2007.
A post mortem conducted in the regional veterinary development centre (RVDC) in Kanglung showed the birds had suffered from an outbreak of fatty liver haemorrhagic syndrome (FLHS), a rare condition in chickens.
An extremely enlarged liver, almost occupying whole of the abdominal cavity, and a large amount of fat deposit in the abdominal cavity were found in the dead birds.
The head of the RVDC centre, Dr S.B. Chamling Rai, said, though the centre had not given a report, the faults were pointed out and corrections made accordingly.
Dr Rai explained: "It made more sense to the workers in the farm if I corrected their practices, than to tell them simply that the chickens have died of FLHS. So I went to the place numerous times and explained."
In an article, Dr Rai says that FLHS is a disease in chickens and other birds, which affects only hens. Birds with this disease have large amounts of fat deposited in their liver and abdomen. This often results in an enlarged soft liver that is easily damaged and prone to bleeding. In some cases, the disease is fatal, usually as a result of blood loss from an internal haemorrhage in the liver. The liver contains many blood vessels that rupture easily during straining to lay egg, resulting in massive bleeding and death.
Dr Rai, an animal health specialist, said the outbreak arose from the high-energy diet and poor management of the chicken farm. The high energy diet was procured from Karma Feeds, the only animal feed producer and supplier in the country.
This was proved as the syndrome did not occur when the remaining chickens were given feed brought from a different company in the neighbouring Indian state of Assam; and also with a few corrective management practices advised to the workers at the farm.
Excessive dietary energy intake is believed to be the cause of FLHS. Though not the entire cause, heredity, he said, may also play a role. When laying hens are fed diets containing high levels of dietary energy, the hens tend to deposit excess energy as fat deposits in their bodies, especially the liver.
Another veterinary source said such a condition occurs if chicken were fed a diet with a high level of energy (fats) over a long period, according to Kuensel Online.
The veterinary official said: "It doesn't happen at once and is a cumulative effect of having high levels of energy in the diet. Having said that it could also be caused by several other factors as well."
Generally, the disease has few or no symptoms prior to the bird's death. The condition is most often seen in birds that appear to be healthy and in a state of high egg production. As a result, death can occur quite unexpectedly. Non-laying hens will not eat as much of the high-energy feed and therefore are not affected as much as high producing hens.
Research says some strains of chicken are more susceptible than others, as also found in the case of this incident. The farm had chicken brought from several sources but only those birds bought from Kolkata in India, were affected, according to the manager.
Dr Rai said that the problem could be contained if the hens are fed diets that contain proper amount of all nutrients. “In our context high-energy ingredients are corn or oilseed cakes," he said.
Meanwhile, the owner is waiting for the report.
"I'm a businessman so it doesn't affect me as much as the farmer," said the owner, Pema Dorji, who also owns the Pema bakery in Trashigang town. Each bird is worth Nu 200, he said.
"I'm waiting for a report of the post mortem because I have to take action accordingly," he said, adding he would talk with the feed supplier if his birds had died because of the quality of feed.
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