A nationwide survey of coccidial infections in chicken farms has not been reported in Japan since 1994. We conducted a field survey of chicken farms between January and March 2007, in collaboration with the livestock hygiene service centers of 41 prefectures, by collecting fecal samples and obtaining farm information through questionnaires. Oocysts were counted and classified into acervulina-, tenella-, and maxima-types on the basis of oocyst sizes. Oocyst detection rates were 72% and 49% in broiler and layer farms, respectively, and the former had a higher rate than the latter. Broiler farms using windowless-type chicken houses and layer farms rearing chickens in cages had lower oocyst detection rates. Detection rates of oocyst types among oocyst positive broiler and layer farms were 76% and 79% for the acervulina-type, 83% and 60% for the tenella-type, 50% and 13% for the maxima-type, respectively. The detection rates of the tenella- and maxima-types were higher in broiler farms. The detection rate of maxima-type oocysts in broiler farms doubled compared with the rate in 1982. Anticoccidial substances and vaccines were in use for the prevention of coccidiosis in 31% and 23% of broiler farms, respectively. Some farms were considered not aware of their use of anticoccidials as feed additives.
(Research Team for Bacterial/Parasitic Diseases)
References:
Nakamura Y. et al. (2010) Bull. Natl. Anim. Health, 117: 1-10
