Released Feb. 19, 2008
COLLEGE STATION, Texas -- Reducing prenatal death in gestating swine turned out to be a relatively easy method discovered by a group of scientists, but it required expertise in both animal nutrition and reproductive biology to solve a complex problem that’s puzzled geneticists for years.
The Texas scientists’ teamwork has paid big dividends, allowing the number of piglets born alive to increase by two per litter and live litter birth weight by 24 percent.
The change is due primarily to an arginine-adjusted diet during a critical period of gestation, said Dr. Guoyao Wu, a Texas AgriLife Research animal nutritionist in College Station and Faculty Fellow in the department of animal science at Texas A&M University. Arginine is an amino acid and can be found in a variety of foods.
The new discovery could lead to solving fetal growth restriction in other mammalian species, including humans and sheep, Wu said.
“In humans, 5 percent to 10 percent of newborn infants have Intrauterine Growth Retardation (IUGR; impaired growth and development of the fetus),” Wu said. “There is no treatment available, and no one knows about the mechanisms responsible for IUGR. With the new knowledge gained from animal studies, we hope to treat IUGR in humans.”
Wu, Dr. Fuller W. Bazer, distinguished professor of reproductive physiology at Texas A&M, and scientists at Texas Tech University discovered sows do not receive enough nutrients during mid-to-late gestation to support the rapid growth of their fetuses and mammary tissues.
“These nutrients include arginine, an amino acid that is one of the building blocks for tissue proteins. This nutrient also regulates key metabolic pathways that are essential to health, growth, development, and reproduction,” Wu said.
By supplementing a standard corn- and soybean-based diet for gestating swine with an additional 0.83 percent arginine between days 30 and 114 of gestation, it greatly reduces prenatal death.
“In 1996, our collaborative team of animal nutritionists and reproductive biologists discovered an abundance of arginine in the pig fetus,” Wu said.
On day 40 of the pregnancy, the allantoic fluid is about 4-6 millimoles/l liter compared to maternal plasma levels of approximately 0.1 millimoles/l liter .
“We’re talking about a 40- to 60-fold increase during that time of pregnancy,” Wu said. “We figured that arginine must be doing something critical to fetal growth and survival.”
The additional two pigs per litter has economic advantages for the pork industry, Wu said.
“We calculated that two newborn pigs per litter could result in an increased profit of $90 per litter,” he said. “That’s very beneficial to the pork producers.”
Wu said the discovery never would have been possible if it hadn’t been for combining researchers with both animal nutrition and reproductive biology expertise. He also emphasized that Bazer and Dr. Sungwoo Kim, adjunct professor with Texas A&M animal science, played a key leadership role in this discovery.
“It was truly interdisciplinary research,” he said. “That’s why we were able to solve this significant problem.”
The research has been published in the Journal of Nutrition (http://jn.nutrition.org/).
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http://agnews.tamu.edu/showstory.php?id=356
Contacts: Blair Fannin, (979) 845-2259, b-fannin@tamu.edu
Dr. Guoyao Wu, (979) 845-2714, g-wu@tamu.edu
