A TEAM of researchers has demonstrated that when a bacteria-derived protein was fed to worm-infected swine, the infection was nearly completely eliminated.
Intestinal parasitic roundworms are host species-specific and can be found in pigs, cats, dogs, humans and other animals. A roundworm specific to humans, Ascaris lumbricoides, is rarely seen in developed countries. Still, about 1 billion people are infected with this species of worm worldwide, usually via some contact with feces.
When A. lumbricoides infects children, nutrient deficiency, respiratory distress, stunted growth and immune defects occur. In extreme cases, infection can cause a life-threatening gut blockage. Worms can also migrate into the bile ducts and the permeable membrane that covers the abdominal organs.
The parasitic roundworm that commonly infects pigs is Ascaris suum, which is so genetically similar to A. lumbricoides that some evidence suggests that they are the same species. A. suum infection in pigs is considered a good model for A. lumbricoides infection in people because of its similar migration through the body to the intestines.
The research team included microbiologist Joseph Urban and his colleagues at the Agricultural Research Service's (ARS) Beltsville Human Nutrition Research Center in Maryland and Raffi Aroian and Yan Hu at the University of California-San Diego.
In the experiments, the team used a crystal protein provided by Aroian's group called Cry5B, which is derived from the soil bacterium Bacillus thuringiensis. Cry5B protein is considered nontoxic to vertebrates and mammals, but it has been used as an insecticide in the past. A. suum genetically expresses receptors for Cry5B.
Previously, Aroian and his colleagues had shown Cry5B to be toxic to hookworms. In laboratory tests, Cry5B triggered activation of stress response pathways in Ascaris larvae and adults similar to that observed with other worms.
"Feeding two moderate doses of Cry5B to pigs resulted in nearly complete elimination of intestinal A. suum infection, and all intestinal roundworm larvae were damaged or destroyed," Urban said. "The dosage we provided in this study is comparable to the dose range used in existing commercial anti-parasitic drugs."
There is a need for more practical delivery systems for anti-parasitic drug treatments, according to the scientists. Cry5B holds potential for use where worm resistance is becoming a problem, especially among ruminant livestock.
The University of California researchers have filed a patent application on the protein expression, and further cooperative research with ARS is being planned.
"These results show the potential of Cry5B to treat Ascaris infections in pigs and other livestock and to work effectively in the human gastrointestinal tract," Urban said.
Korean swine industry
While Korea's hog inventory has increased to more than 9.9 million head in 2013, Korea's demand for pork has outpaced its production.
Primarily due to its inability to supply high-quality pork at competitive prices, the Korean swine industry is looking for new ways to be more efficient. This sector is very important for sustaining Korea's demand for U.S. grains, as it used 3.3 million metric tons of grain in 2013, or about 27% of the nation's total demand for grain.
Ineffective swine health management, inadequate business management and inefficient marketing systems are blamed for the low productivity and high cost of Korean pork. In looking to expand, the industry has experienced enormous difficulties. Scarcity of land, lack of social acceptance, enforced environmental regulations and more stringent manure management regulations are a few of the obstacles local producers face.
The U.S. Grains Council (USGC) hosted a webinar for 60 Korean swine farmers, managers, extension agents and others about a method to improve efficiencies in the Korean swine industry, during which a USGC consultant discussed management of a wean-to-finish system.
Wean-to-finish swine systems are an innovative concept in Korea. Typically, Korean swine producers raise hogs to market weight at one location. To supplement the industry's limited knowledge, the webinar informed participants about facilities needed for a wean-to-finish operation, how to start pigs successfully on feed when they arrive at the location and the most up-to-date management and feeding tips.
USGC has worked with the Korean swine industry from the beginning of its presence in Korea in 1972 and was instrumental in bringing modern production practices and management knowledge to the sector. The council said it will continue to provide educational webinars and other programs to this important sector in Korea.
Alcohol is a common ingredient in meat marinades, but the Templeton Rye Distillery in Templeton, Iowa, is trying to eliminate the extra step of adding alcohol by producing whiskey-flavored pork.
Nick Berry, a friend of the company's founders who has a Ph.D. in animal science, is raising 25 Duroc pigs for the distillery. The plan is to change the pork's flavor by feeding the pigs a diet that includes dry distillery grain left over from the whiskey-making process.
While the pork may taste different from hogs fed a regular diet, swine nutritionists have expressed doubt that the hogs will actually have a strong whiskey flavor, mainly because the hogs are eating the distillery byproduct and not straight whiskey. In fact, distillers grains from the ethanol process have been fed to hogs for years.
Nonetheless, the Templeton Rye Pork Project has already received a number of inquiries, including one from celebrity restaurant owner Stephanie Izard, a "Top Chef" winner. The company said the hogs will be ready in June, upon which it will then decide where they will go.
Student swine research
Some student employees at Iowa State University are playing a vital role in research on critical issues in today's swine industry.
Assistant professor in agricultural and biosystems engineering Dan Andersen said a three-university research project focusing on the causes of manure pit foaming offers great opportunity for student involvement.
"People from the University of Illinois, the University of Minnesota and Iowa State have been working together on this project," Andersen said. "Faculty, staff and students all having a variety of backgrounds is beneficial because it gives different perspectives. There are about 10 people from Iowa State involved, including four students. We generally hire students from within the department, although they might not have similar previous experiences."
Mark Van Weelden is one of those students. As a civil engineering graduate student with a passion for water treatment, his experience has been both unique and valuable. He said Anderson "took me under his wing and helped me learn more about the project. I never thought I would ever touch manure."
Yet, in 13 months, Van Weelden has worked with others to collect monthly samples from foaming and non-foaming pits on 50 farms. The samples were tested for methane gas production, viscosity and other factors in an effort to determine necessary factors for the foaming to occur. This, in turn, could help researchers develop recommendations on how to lessen the chance for foaming to ignite and cause damage and injury to people or animals.
"The discovery of how much methane gas is produced by various samples was the most helpful," Van Weelden said. "Although it didn't solve the problem, it has helped researchers better understand the foaming."
Currently, researchers are working on how different feed combinations affect manure composition.
"This has been very interesting because it affects real people, and it is something that is not already figured out, so you have to think from all levels," Van Weelden said.
He said he feels that everyone should do some type of research at some point in their career and that Iowa State is a great place for students to learn about research, even if that's not what they think they want to do for a career.
"You will learn something new, and you will learn how to think differently," Van Weelden said. "Iowa State is a great university because it has a considerable amount of opportunities in research for students."