by: Heather Smith Thomas
The body condition and nutrition of the dam can make a difference in some of the traits that ultimately are exhibited by the developing fetus. Studies are now underway at the University of Wyoming to explore this phenomenon in beef cattle.
Dr. Rich McCormick, Professor of Muscle Biology, is involved with this project. “We usually use a sheep model because it is quicker and easier than doing it in cattle, but we're starting to investigate this in cattle,” he says.
The initial concern was from observations in humans, with Barker's Hypothesis—which was inspired by the “Dutch Hunger Winter” story. “Towards the end of World War II the combined British and American operation dropped a lot of troops beyond the German lines in an effort to secure the bridges over the Rhine River. We figured we would end the war right then, but miscalculated. We didn't realize the Germans still had a lot of fighting ability and it was a military disaster,” says McCormick.
The Dutch people in the Amsterdam area were enthusiastic about being liberated by the Allies and started flying British and American flags. “When that operation was all over, most of our troops ended up in German prison camps and the Germans were angry and vindictive; they halted all food shipment into that part of the Netherlands. People were down to about 400 calories of poor food per day, or less. They were eating everything possible, including their tulip bulbs, grinding them up and trying to make them into bread,” he says.
“This was a part of the world where they kept good medical records, so Dr. Barker followed the medical history of some of these people, including women in various stages of pregnancy during this period of famine—and followed their offspring who were born in 1944-45. Later in life, these people developed all sorts of terrible things, including serious heart problems, diabetes, etc. Currently there is more research looking at what happens as a result of conditions the fetus undergoes in utero,” he says.
Many of these things will depend on what stage, what trimester, the pregnancy is in when the nutritional status of the mother is adversely affected—and the severity of the nutritive restrictions. “There are different problems that crop up,” he explains.
Studies have been done in various laboratory animals, and it has also become of interest in agriculture. “Here, we also started looking at the problem of maternal obesity, especially in humans. In third world countries, nutrient restriction is the bigger problem, but in this and some other countries we are seeing a lot of maternal obesity,” he says.
“My area of expertise is connective tissue, such as collagen. Maternal obesity can severely impact the offspring when they grow up. Having an overly obese mother may actually be worse than having nutrient restrictions,” says McCormick.
This is also true in horses. Foals from obese mares grow up to have metabolic problems like insulin resistance and are more prone to developing laminitis and Cushing's Syndrome.
“What interests me in the offspring of obese humans and cattle is the inflammatory response that is initiated. This has great implications for connective tissue, skeletal muscles and the heart,” he explains. Thus this could be an important issue in animals produced for food.
“You can make a clear case for this in human health, and in cattle we get deposition of connective tissue fibrosis in the heart. What I've worked on for most of my career is collagen cross-linking. All evidence suggests that connective tissue is impacted during this fetal programming—maybe even to the point of contributing to tougher meat or the variability in meat tenderness from different animals. This is a big issue in the beef industry,” he says.
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