Embryonation Of Ascaridia Galli Eggs In Various Laboratory Media And Their Infectivity In Broiler Chickens:- Nwosu Goodluck C.

ABSTRACT The embryonation potential of some commonly used laboratory media for Ascaridia galli eggs was investigated and the subsequent infectivity of the embryonated A. galli was examined in young broiler chickens. The media are some commonly used fluids/solvents in laboratories namely phosphate buffered saline (PBS), physiological saline, distilled water, normal saline, tap water, 2.5% potassium dichromate and 5% formalin. A. galli eggs were isolated from adult A. galli worms harvested from slaughtered layer chickens. The female worms were macerated in coffee strainers placed in Petri dishes to recover A. galli eggs. The macerations of the worms, washing and culture of the eggs involved one medium or a combination of media. In one case, the worms were macerated with PBS and the egg suspension washed with distilled water before culturing with normal saline. While in other * cases only one media was involved the egg cultures in various media were set in Petri dishes cultured on bench tops in the veterinary parasitology laboratory of MOUAU at room temperature (27-28%). The embryonation process was monitored every three days by slightly agitating to mix the suspension and to disrupt any fungal growth, and taking and examining a drop of the egg suspension from each of the cultures. At the end of the culture period (day 20), the egg suspension for each medium was eggs and larvae were quantified in each case. that medium and preserved in such medium in the refrigerator (4° C) and used within two weeks for the experimental infections. The birds which were placed in groups of six each were infected orally using 2ml syringe without a needle to deliver the egg suspension and one group remained as uninfected control. All egg suspensions from each medium were adjusted to contain 700 embryonated/larvated eggs in one ml ofthe egg suspension, the dose each bird received. Body weights faecal egg counts, and worm burdens weretaken at the end of the study following post mortem examination were recorded. Embryonation occurred in all the media investigated. Infection became patent in all the infected birds and was evident by presence ofA. galli eggs in the faeces of birds. There was variation in the faecal worm egg counts between groups. It was concluded that the various media or media combinations supported embryonation ofA. galli eggs as much as the standard embryonation media and the embryonated eggs were infective in the birds. The various media could therefore be used for t embryonation ofA. galli eggs for both in vivo and in vitro studies.