Comparison of two methods of Marshallagia marshalli donor sheep production.

Marshallagia marshalli is found in the abomasums of sheep, goats and wild ruminants in tropical and sub tropical climates. In Iran among different species of Ostertagiinae that can infect sheep, M. marshalli is currently the major cause of parasitic gastroenteritis in ruminant. Having a donor animal is essential for various studies. In the present study we compared the efficacy of two different method of M. marshalli donor sheep production. In the first method, M. marshalli donor sheep was produced by transplanting of adult forms of this worm into abomasum of a lamb (6 months of age) through a surgically established cannula. In the second method, 5,000 infective larvae (L3) from the female M. marshalli culture were given to a worm-free lamb of 6 months age through a stomach tube. After 3 days of transplanting, few eggs of M. marshalli appeared in the cannulated lamb's faeces. The number of eggs per gram of faeces (EPG) increased in the following days. The average number of EPG reached up to 23.5 ± 11.26 per day in 2 months. In larval infected lamb by day 21 post infection the eggs were appeared in faeces. The average number of EPG reached up 53.5 ± 42.5 per day in 2 months. In comparison between cannulation and larval infected, the number of eggs laid by worms transplanted in cannulated lamb was less than that of larval infected lamb. However, the abomasal cannulation method seems more preferable due to some advantages such as defined number of worms transplanted into abomasums, rapid access to the eggs and their culture.