*Krissa Welshans holds a bachelor's degree in animal science from Michigan State University and a master's degree in public policy from New England College. Welshans has long been involved in agriculture and has worked with numerous agricultural groups, including the Animal Agriculture Alliance.
TO aid in the formulation of livestock diets, researchers at the University of Illinois have determined the digestibility of energy and amino acids in fermented soybean meal.
Hans H. Stein, a professor of animal sciences at the University of Illinois, explained that soybean meal contains anti-nutritional factors such as oligosaccharides and antigens that restrict its use in diets fed to weanling pigs. Fermentation of soybean meal eliminates some of these anti-nutritional factors, making fermented soybean meal a potential lower-cost substitute for animal protein in starter diets.
Soybean meal fermented in the presence of Aspergillus oryzae and Lactobacillus subtilis has recently become available to the U.S. market, which, according to Stein, prompted the study.
"Fermented soybean meal contains fewer anti-nutritional factors and is well tolerated by weanling pigs, but there is a lack of data on the digestibility of energy and amino acids. So, our goal was to determine those values," Stein said.
Stein's lab conducted two experiments. The first determined the concentration of digestible energy (DE), metabolizable energy (ME) and net energy (NE) in fermented soybean meal. The second determined the standardized ileal digestibility of crude protein and amino acids. Both studies included conventional soybean meal and fish meal for comparison.
On a dry matter basis, fermented soybean meal contained 4,296 kcal/kg of DE, 3,781 kcal/kg of ME and 2,710 kcal/kg of NE. Stein said these values compared favorably to those in fish meal, which contained 3,827 kcal/kg of DE, 3,412 kcal/kg of ME and 2,450 kcal/kg of NE.
DE, ME and NE were decreased in fermented soybean meal compared with conventional soybean meal, which contained 4,553, 4,137 and 2,972 kcal/kg of DE, ME and NE, respectively.
"Fermentation of soybean meal removes sugars and oligosaccharides," Stein explained. "Sucrose is easily digested by pigs, and oligosaccharides are almost completely fermented. When these are removed, the remaining meal contains a greater percentage of fiber, which reduces the digestibility of energy in the diets," he added.
Digestibility of crude protein and amino acids in fermented soybean meal was the same as or greater than that of soybean meal. Digestibility values for most amino acids were greater in fermented soybean meal than in fish meal.
Stein said the results of the studies indicate that fermented soybean meal could replace fish meal in starter diets without negatively affecting the energy content or digestible amino acid content of the diets.
"With this new product on the market in the United States, producers have another option for providing protein in weanling pig diets," he said.
Swine disease research
A researcher in the Virginia-Maryland Regional College of Veterinary Medicine has received a two-year, $150,000 post-doctoral fellowship grant from the U.S. Department of Agriculture to investigate how porcine circovirus type 2 (PCV2) depletes the lymphatic system and causes inflammation in pigs.
Shannon Matzinger, postdoctoral associate in the college's department of biomedical sciences and pathobiology, seeks to better understand the cause of the global swine disease that has caused significant economic losses since its first discovery in the late 1990s.
"Although this is arguably one of the most economically important pig viruses, we still do not fully understand the mechanism for how it causes disease," Matzinger said. "If we can identify the underlying mechanism that causes the disease, we can design better control and prevention strategies against the virus."
Scientists first identified non-pathogenic porcine circoviruses in contaminated kidney cells in 1974 and the pathogenic strain in pigs with postweaning multi-systemic wasting disease in 1998. The disease can cause respiratory issues, intestinal disease and reproductive problems and primarily infects the lymphatic system.
Dr. X.J. Meng, university distinguished professor of molecular virology and Matzinger's mentor for this fellowship grant, explained that although vaccines against PCV2 have been on the market since 2006, emerging variant strains of the virus and rare cases of vaccine failures still threaten the swine industry.
He and Matzinger said they hope to identify some of the genetic factors in the host cells and the genome of the virus that may be wreaking havoc on the immune system of infected pigs.
"One of the questions that remain unanswered is how porcine circovirus type 2 is depleting the immune system," Matzinger explained. "If we can answer this question, we will understand a key component of the viral pathogenesis and disease progression."
Matzinger specifically will be testing a hypothesis that the virus encodes viral micro-RNAs — molecules that play an important role in the regulation and expression of genes — that obstruct the immune system's ability to detect the virus either by maintaining low levels of virus replication or preventing specific cells in the immune system from communicating with each other.
Matzinger's long-term goal is to pursue an academic career focusing on host/pathogen interactions and the development of interventions against viral animal diseases. Matzinger previously earned her Ph.D. from the University of California-Davis Center for Comparative Medicine, where she studied the role of host immunity in controlling influenza virus replication.
Meng's lab studies the molecular mechanisms of viral replication and pathogenesis and develops vaccines against emerging, re-emerging and zoonotic viral diseases. In 2006, the lab invented the first fully USDA-licensed vaccine against PCV2 and associated postweaning multi-systemic wasting syndrome in pigs, and the vaccine is now commercially available worldwide.
Earlier this year, the lab received two grants from the National Institutes of Health: a $1.6 million grant to study cross-species infection of the hepatitis E virus and a $2 million grant to investigate chronic infections of the hepatitis E virus. It received another $500,000 grant from USDA to identify protective T-cell epitopes against porcine reproductive and respiratory syndrome virus.
Meng and his colleagues also recently tracked the origin of the U.S. strains of emergent porcine epidemic diarrhea virus.
Swine reproduction guide
The U.S. Pork Center of Excellence announced that it has launched the "National Swine Reproduction Guide," a web-based application offering valuable information to hog producers.
The troubleshooting and management guide, built in a user-friendly and intuitive format, contains extensive information and support for pork producers, including more than 1,000 fact sheets and references, the center said.
"This guide is designed to help producers identify the source of the reproductive problem they are experiencing and, through research-based fields, provide information directly related to that problem," said Chris Hostetler, animal science director at the National Pork Board.
The guide uses a reproductive decision tree that begins with three categories: gilts, sows and boars (semen). After selecting a category, a list of potential issues are available from which to choose, such as "low farrowing rate" or "too small of a gilt pool."
Once the topic is selected, the decision tree helps narrow the search on the issue through a series of available questions. After choosing the question that best fits the original problem, an answer is provided in the form of a fact sheet with viewable references.
The guide is available only as a web application via www.usporkcenter.org and may be accessed through personal computers, smartphones and tablets.