The effectiveness of D. flagrans has been verified worldwide.

Published studies have been reviewed by Knox (2003), Soder and Holden (2005), Ketzis et al. (2006), Jagla et al. (2013) and Terry (2013), and these are summarised.

The following should be noted:

1. Strains of D. flagrans: A variety of strains have been used in these studies, including isolates originating from Denmark, Brazil, India, Mexico and Australia (including strain IAH 1297).
   
2. Dosage: The daily dose rates varied widely, for most isolates 5 x 10⁵ spores/kg bodyweight/day was commonly used, for strain IAH 1297 a dose rate of 3 x 10⁴ spores/kg bodyweight/day was sufficient.
   
3. Passage through the digestive system: In these trials the spores were fed to the animals and were required to pass through the recipient animal’s digestive system in order to exert their control effect in the manure.
   
4. Animal species: Efficacy has been demonstrated in sheep, cattle, horses, goats, pigs and a variety of zoo animals i.e. in animals with ruminant, hindgut-fermenting and mono gastric digestive systems.
   
5. Trial locations: Trials were conducted in Europe (Denmark, Sweden, Switzerland, Germany, Netherlands, France, Spain, Lithuania, Serbia), the USA, Mexico, Brazil, Argentina, Australia, New Zealand, South Africa, Malaysia, China and India.
   
6. Worm types: It was found that the treatment was applicable to a wide variety of worm genera, including Haemonchus, Cooperia, Teladorsagia, Trichostrongylus, Oesophagostomum, Dictyocaulis, Trichuris, Strongyloides, cyathostomes, Strongylus, Nematodirus and Mecistocirrus. Also, for each species of animal the main worm types found tended to remain the same, regardless of the geographic location of the trials.
   
7. Trial dates: Successful field trials with D. flagrans have been conducted for many years, covering a period from 1993 to 2013 and remain ongoing.
   
8. Trial types: A variety of study designs were used, the most common being:
   

a. Controlled grazing studies: The spores were fed to worm-infected animals (seeders) as they grazed on pasture and selected parasitological parameters were monitored periodically. The results were compared with those of a matched control group, which received a placebo product. In some studies worm-free tracer animals were grazed on the trial paddocks in order to provide an additional measure the degree of pasture infectivity.

b. Controlled Pasture Plot studies: Faeces from worm-infected animals that had been fed with D. flagrans were collected and manually placed on pasture. These samples contained both worm eggs and D. flagrans spores. The pasture surrounding these faecal pats was periodically tested to determine the degree of infection by parasite larvae and the results were compared with those for matching faecal pats which contained worm eggs only (no D. flagrans).

Did you know: Trials with Duddingtonia flagrans have shown significant parasitic nematode reductions on pasture of grazing species like sheep, goats, cattle and horses