attenuation effect of uv on haemonchus contortus larvae in experimentally infected goats.

background: haemonchus contortus causes severe economic losses in small ru-minants, so this study was conducted to study the uv effect on h. contortus larvae and its protective effect. methods: sixteen male goats were divided into 5 groups, control infected, con-trol uninfected and uv 30minutes exposure; uv 60minutes exposure and uv booster 60minutes exposure. the uv groups were exposed to uv irradiation at wave length 254 nm for 30 and 60 minutes. the uv booster 60min was ad-ministrated 2 doses of exposed larvae with an interval of one month. all groups except the control negative one were challenged for 42 days from the beginning. results: in uv booster 60 min had reduction in egg count per gram feces and worm burden (93% & 34 % respectively). the establishment rate and relative fertility declined in comparison with other groups. these parameters were simi-lar in control infected, uv 30min and uv 60min groups. pcv value of uv booster 60min group was similar to uninfected group. after two weeks from the booster dose of irradiated larvae, increased levels of antibody were found in goats of uv booster 60min group. conclusion: two doses of uv 60min exposure, with an interval of one month, gave reduction not only in egg per gram feces but in worm burden as well.