CHICK KILLER DEFEATED

Press, Volume CXV, Issue 33963, 2 October 1975, Page 12

CHICK KILLER DEFEATED

A poultry disease which has plagued chicken farmers since fowl were first domesticated has been brought under control in recent years. Marek’s disease — named after the person who identified it — took a heavy toll of chickens for years,

sharply cutting into the poultry farmers’ profits. The disease has been known since 1908. It affects the viscera, nerves and blood and usually attacks young chickens. It becomes noticable within the first six weeks and reaches a peak — more often than not causing death — at about 14 weeks. Affected birds that survive usually never regain

full health and never achieve good egg production. The breakthrough in fighting the disease came in the late 1960’s .when a new vaccine was perfected. The vaccine is made from a herpes virus found oddly enough in another member of the poultry family, the turkey. There are some drawbacks with the vaccine. For instance, it must be stored at minus 100 degrees Celsius, which means the

farmer cannot simply keep it in his home refrigerator. But the economic advantages are good. The vaccine costs less than 10 cents a bird. It is administered by injection when the chickens are one day old and drastically reduces any loss of birds. It has been found that vaccination also increases egg production by four to five per cent, compared to non-vaccination. The vaccine has been used in New Zealand for about three years.