Factors Associated With Newcastle Disease Occurrence In Indigenous Free-range Chickens In Embu And Mbeere Districts

Abstract

A study of factors associated with outbreaks of Newcastle disease (ND) in indigenous free - range chickens was carried out in five agro - ecological zones in t wo districts of Eastern province of Kenya. Seventy five households keeping chickens were randomly selected. Data on management practices, incidence of diseases and factors associated with ND outbreaks were collected using interviewer - administered questionn aire. The prevalence rate of Newcastle disease was highest (93.8%) in the dry zone (Low midland 5) and lowest (50%) in cool wet zone (Lower highland 1). The ND outbreaks were significantly associated with stress inducing factors, namely: confinement of bir ds, lack of supplementation of feed and seasons. It was found to be more prevalent in wet seasons than dry seasons in all agro - ecological zones, except the Lower midland 5, where it occurred during the hot season. Other important factors for the outbreaks were: mode of disposal of infected birds, carcasses and fecal matter, windy conditions and the restocking of farms with chickens from the markets. Mixing of chickens with other poultry, green vegetation on the farm, dust storms, gift birds to farms, short intermittent temperature changes and flowering of the crops had minimal association with these outbreaks. The study also revealed that only 17.3% of the farmers were controlling ND through vaccination. It was concluded that besides using vaccination as a c ontrol measure for ND in rural free - range poultry, the flock owners should be educated on the modes of transmission of ND virus, in addition to being discouraged from purchasing restocking chickens from the market