Dung-derived biological agents associated with reduced numbers of infective larvae of equine strongyles in faecal cultures.

The article studies the effect of soil organisms derived from dung on the numbers of infective larvae of equine strongyles in horse faecal cultures. It was observed that high inoculum of soil organisms significantly reduced the number of strongyle larvae, potentially through predation.

Research Methodology

• Two types of soil organisms were used, derived from manure-fertilized soil (MA) and chemically-fertilized soil (CH).
• These organisms were cultured separately in a laboratory setting.
• Organisms obtained from these cultures were added to horse faeces containing strongyle eggs to form three different treatment groups: one without any soil organisms, one with low inoculum, and one with high inoculum of soil organisms.
• Three different studies were conducted using varying combinations of MA or CH cultures with differing concentrations of strongyle eggs in the horse faeces.
• Post-incubation, free-living and parasitic nematodes were recovered and counted.

Major Findings

• The research found that the numbers of third stage larvae (an infective stage of the strongyles lifecycle) were significantly lower in the high inoculum group compared to the controls. This suggests that the soil organisms may decrease the viability of strongyle eggs in the faeces.
• The reductions in larvae numbers were shown to be proportional to the number of soil organisms added to the cultures, indicating that mortality of the larvae increased with the number of soil organisms.
• On examination of the source cultures, the presence of two species of fungi and three genera of free-living nematodes reported to be predacious were detected. These organisms likely play a role in the reduction of strongyle larvae numbers, potentially through predation.

Implications and Conclusion

• The study highlights the potential biological control strategy against parasitic strongyles in horses using soil organisms present in equine dung.
• Further research could investigate the specific interactions and mechanisms that result in the observed reductions in larvae numbers.
• It also calls to attention the potential importance of the dung and soil microbiome in controlling parasitic infestations, deserving of further exploration.