AN INVESTIGATION ON DIFFERENT MEDIA FOR EMBRYONATION OF ASCARIDIA-GALLI EGGS

Ascaridia galli eggs were isolated from chicken faeces or from mature female worms. Eggs from both sources were embryonated in 0.1N sulphuri c acid, 2 % formalin and vermiculite, respectively. The different cult ures were incubated at 18 degrees C for 5 weeks. For eggs cultivated i n vermiculite 95 % developed into the third larval stage. Only 26 % of the eggs isolated from worm uteri and cultivated in 2 % formalin deve loped into the third larval stage, whereas 62 % of the eggs isolated f rom faeces and cultivated in 2 % formalin developed into the third lar val stage. For eggs isolated from worm uteri and cultivated in 0.1N su lphuric acid, 41 % developed, in contrast, eggs collected form faeces and incubated in 0.1N sulphuric acid, started to rot (mixture of bacte ria and fungi) after one week in the incubator. Week-old chickens were orally infected with doses of 500 fully developed eggs to test the in fectivity of the 5 cultures. Eight weeks post-inoculation, faecal samp les were taken from all chickens before slaughter and the egg excretio n was determined. Furthermore, A. galli were recovered and counted. Th e infectivity of eggs originating from different embryonation methods was compared. The results indicated that eggs collected from uteri and embryonated in 0.1N sulphuric acid resulted in high infection rates w ith evenly distributed worm populations and high egg counts. It is rec ommended to use A. galli eggs harvested from worm uteri and embryonate d in 0.1N H2SO4.