The USDA recently awarded $499,542 to the University of Minnesota, Kutztown University and Rodale Institute for a 3-year NIFA Organic Transitions grant to explore manure and pasture management strategies that can control swine parasites in organic pig production.

Parasites are a persistent obstacle in organic swine production. They not only present challenges of poor animal health and welfare, suboptimal productivity and efficiency to organic farmers, they may also become potential threats to food safety and the environment. Research targeting solutions to parasite control in organic pig production is paramount and much needed.

The modern day pig hasn’t changed much from those that walked the earth thousands of years ago. At the core, a pig is an omnivorous animal well-adapted to foraging. When pigs are raised solely indoors, instinctual behaviors quickly become restricted. For example, pigs reared in poor indoor environments (pens that restrict movement, concrete floors, artificial lighting) develop symptoms indicative of chronic social stress that can affect daily weight gain. This becomes even clearer with direct comparisons between indoor and outdoor production systems.

There is growing evidence to support the claim that meat quality and animal welfare are improved by grazing pigs outdoors.

However, in order for organic pig operations to remain economically competitive with industry standards, additional high quality, low-cost feed sources and novel integrated crop-livestock management strategies are required to finish pigs. These strategies must additionally consider the control of swine parasites without prophylactic treatments, which is challenging considering that semi-free-ranged pigs can be infected with a higher diversity of parasite species at higher abundances relative to those in non-organic, indoor industrialized production operations.

Unlike their conventional counterparts, organic swine operations struggle with the lack of options for parasite management. Surveys of organic farms have shown that pigs are infected with more types of parasites at a higher prevalence and intensity of infection. Bedded floors and access to outdoors or pastures that are required by the National Organic Program are the major sources of parasite contamination on organic pig farms. Compared to conventionally raised pigs housed on slatted floors, organic pigs harbor more species of parasites with heavier concentrations. It is worthwhile to note that although these conventional niche pig farmers used similar housing systems such as bedded floors with outdoor access, they applied anthelmintics (a.k.a. dewormers) to control parasites, which is restricted in organic agriculture. However, there has not been a comprehensive study of parasite prevalence on organic pig farms in the United States so the extent of the problem is almost completely unknown.

Project Objectives

• Evaluate parasite prevalence on organic pig farms.

• Determine the effectiveness of manure composting on eliminating swine parasites and its underlying mechanisms.

• Assess biofumigation as an approach to swine parasite control in pastures.

• Determine effects of grazing biofumigation pastures by organic pigs on reducing swine parasite contamination.

The project team plans to use four approaches to address swine parasites in pastured pig operations.

First, a comprehensive study of parasite prevalence on organic pig farms will be completed. Project leaders will conduct farm visits across four states, states representing about 30 percent of national organic pig farms and over 60 percent of national organic pork sales.

Second, swine manure bedpack will be thermophilically composted in windrows as a strategy to eliminate swine parasites and it is predicted that high composting temperatures is the leading mechanism for parasite destruction.

Third, biofumigation will be examined as a pasture management strategy to remove parasites from field soil. Biofumigation — a technique used by crop farmers to manage soil-borne plant pathogens, weeds, insects and nematodes — functions by incorporating specific plant residues into the soil that rapidly release toxic isothiocyanates. Mustard plants (Brassicaceae family), in particular, are often reported on their biofumigation potential, and there is evidence that some mustards have anthelmintic properties. However, using mustards to kill or suppress swine parasites in pastures has never been tested, indicating a novel integrated crop-livestock approach to parasite management.

Lastly, team leaders will investigate two different approaches to incorporating biofumigation pastures into the soil: biologically through pig grazing and mechanically with equipment.

Swine parasite infection and contamination represent significant barriers for transitioning and organic pork producers because there is a lack of organically-approved control measures. Farmers continue to appeal to scientists and Extension agents for options that are substantiated by field and clinical trials. In response, researchers among the University of Minnesota, Kutztown University and Rodale Institute developed this project to address challenges expressed by pork producers.

The long-term goal of this project is to develop manure and pasture management strategies for organic and transitioning pastured pork producers that mitigate swine parasite contamination and transmission. Successful completion of the project objectives will provide producers with effective tools to overcome challenges associated with swine parasites and ultimately increase organic pork production across the U.S.