tailieunhanh - Báo cáo khoa học: " Effect of ultraviolet radiation on the hatchability and survival of eggs and larvae of sheep nematode"

Tuyển tập các báo cáo nghiên cứu khoa học quốc tế về bệnh thú y đề tài: Effect of ultraviolet radiation on the hatchability and survival of eggs and larvae of sheep nematode | J. Vet. Sci. 2004 5 1 59-62 JOURNAL OF Veterinary Science Effect of ultraviolet radiation on the hatchability and survival of eggs and larvae of sheep nematode Ademola Isaiah Oluwafemi and Ademola Janet Ayobami1 Department of Veterinary Microbiology and Parasitology Univeristy of Ibadan Ibadan Nigeria 1 Department of Physics University of Ibadan Ibadan Nigeria The hatchability of sheep gastrointestinal nematode eggs exposed to ultraviolet UV radiation and the activity of the hatched larvae were examined. Hatchability decreased with increasing exposure to radiation. The difference in hatchabilityof eggs irradiated for 15 30 and 60 minutes were highly significant p da and compared with the hatchability of the nonirradiated eggs. The life span of irradiated larvae was shortened only 20 of those expose to UV radiation 60 minutes survive for 2 days as against 100 survival rate in the non-irradiated larvae. Batches of nematode larvae L1 were irradiated with ultraviolet UV light for varying time interval to determine the influence of radiation on the transmission potential of the irradiated larvae. There was a decrease in the survival rate of the hatched free-swimming larvae that corresponded with the increasing radiation exposure time. Key words Ultraviolet radiation hatchability survival nematode sheep Introduction Several authors have reported on the influence of such factors as temperature pH light salinity and redox potential on hatchability of nematode eggs. Radiation influence on a variety of living organisms has been observed to vary from partial to total interference with normal development process 17 14 3 15 . The Nairobi declaration on climatic change in 1990 confirmed a significant increase in trace gases which is responsible for a gradual erosion of the stratospheric ozone layer which is expected to lead to an increase of ultra violet UV radiation at the earth surface. An argumentation of incident biologically effective radiation .