Parasites are ubiquitous in livestock in general and organic livestock in particular due to manage-ment factors promoting transmission (pastures/outdoor runs, plenty of bedding, restrictive use of parasiticides). The parasites cause poor animal welfare, production losses, disease, and non-uniform products. Pig helminths with hard-shelled eggs are difficult to control, as the eggs are highly resistant and may survive for years.
The present project focuses on reducing the transmission of hard-shelled eggs to growing pigs by investigating:
The overall objective is, through close interaction between researchers, advisors and farmers, to develop new strategies to control parasitism in organic livestock. The strategies will ensure high levels of animal welfare (credibility), increased animal productivity (growth), and a minimum reliance on chemical drugs (robustness).
2012: Progress and activities:
Results show that eggs of both the round worm and the whip worm may survive for at least nine years on pastures. As an innovative tool to reduce pasture contamination levels, the project has therefore tested the potential of micro fungi to destroy the parasite eggs. The fungi can degrade chitin which is present in the shells of some parasite eggs. The eggs of the poultry roundworm have thus proven to very susceptible to at least one species of fungi, whereas the shell of the porcine roundworm appears to be generally very resistant to fungal degradation. It is therefore unlikely that micro fungi are suitable for biological control of pig parasites, though they may have a potential against other parasites such as the poultry round worm. The first results indicate that the fungi may be very effective in controlling this particular parasite which is of importance within poultry production.
The project has also collected a large amount of baseline data on the prevalence of parasite infections in pigs and occurrence of parasite eggs in the environment of five organic farms. The last of the data is still being processed, but it is overall clear that eggs of the large round worm are present in the soil of all five farms. The result is that piglets are exposed from early life and bring the infection into the stable, which is then contaminated with eggs. Although most eggs do not seem to develop to the infective stage in the stable, enough do become infective, for the pigs to become reinfected indoors. The results also show that many of the undeveloped eggs in the manure and bedding material are still viable and can potentially continue development if used to fertilise soil. It is therefore being examined how the eggs may be inactivated by high temperatures, ammonia and anaerobic conditions, as present in a compost heap or long-term storage of slurry.
The project has revealed large differences between the parasite transmission patterns of the five farms. The next activities will therefore be to better understand the relative importance of exposure outdoors and indoors, and how transmission indoors may be reduced.
Ultimately, It is believed that the project will help increase the potential for growth of the primary pig production through improved pig productivity and integrated parasite control, promoting a more biological robust livestock system. This will in turn improve the credibility of the sector through better adherence to basic organic farming principles (e.g. better animal welfare through enhanced natural immunity and improved rearing practices to evade parasites).
2011: Progress and activities:
As the project is in its first year it is still in the process of collecting and processing basic information on parasite occurrence in pigs and their environment. More specifically, the long-term survival of eggs on pastures is monitored for optimising pasture rotation schemes. Results show that eggs of both the round
worm and the whip worm may survive for at least 9 years on pastures.
As an innovative tool to reduce pasture contamination levels, the project is examining if micro fungi that can degrade chitin such as is present in some parasite eggs shells can be reduced to pasture contamination levels. Initial results indicate that the fungi can destroy chitin components of the eggs shells but it has also
become apparent that some egg types may contain elements protecting against the fungi.
Secondly, it is studied if and how parasite eggs can survive and develop to infectivity in bedding and faecal material in the stable and manure heap. It is too early for comprehensive data to be available but the aim is to determine how eggs may be inactivated by different factors such as temperature, ammonia and pH.
This will provide better knowledge on hygienic management of manure and help in the overall understanding of how the parasites are transmission within the herds. This will in turn be essential for understanding how to maintain infection levels at acceptable low levels that does not compromise animal health and welfare.
Ultimately, It is believed that the project will help increase the potential for growth of the primary pig production through improved pig productivity and integrated parasite control, promoting a more biological robust livestock system.
This will in turn improve the credibility of the sector through better adherence to basic organic farming principles (e.g. better animal welfare through enhanced natural immunity and improved rearing practices to evade parasites).
Stig Milan Thamsborg
DK-1870 Frederiksberg C
Tel: (+45) 35 33 37 78