Wednesday, May 17, 2017

Dealing with the risk of Avian Influenza

Good biosecurity measures are vital on any poultry farm to reduce the spread of many diseases - particularly serious ones such as Avian Influenza. It is generally a matter of commonsense and putting the right procedures in place. The Vietnam government has produced a booklet advising farmers and the points are relevant here in Australia.
The risk of disease is highest on intensive farms with large numbers of hens. The only AI outbreaks in Australia have been on intensive properties. In a genuine free range environment where hens are in small numbers and have unrestricted access to pasture, disease outbreaks are uncommon if effective biosecurity measures are in place.Many producers ask 'What are the signs of Avian Influenza?' The Vietnamese manual describes the symptoms well.The disease can appear suddenly in a flock, and many birds die quickly, often without having appeared sick. Or there may be signs of depression, little food intake, ruffled feathers and fever. Other birds show weakness and a staggering gait. Sick birds often sit or stand in a semi-comatose state with their heads touching the ground. Some animals, especially younger birds may show neurological signs. Hens may at first lay soft-shelled eggs, but soon stop laying. Combs and wattles are dark red to blue and swollen and may have pin-point haemorrhages at their tips. Watery diarrhea is frequently present, and birds are excessively thirsty. Respiration may be fast and laboured. Heamorrhages may occur on unfeathered areas of skin, especially the shanks of the legs. The mortality rate varies from 50% to 100%. The virus may not show any clinical signs or lesions.

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