While fetal programming has a lot of potential for cattle producers, most of what is known about it started from observations of women who experienced starvation or nutrient deficiencies while pregnant and how that impacted their children throughout their lives.
For example, at the end of World War II from 1944 to 1945, there was an embargo on food transport in the Nazi-occupied Netherlands. Coupled with a severe famine, each Dutch person was rationed to just 400-800 calories a day. This time period became known as “Hongerwinter,” literally, “Hunger Winter” in Dutch.
“Nutrition and Mental Performance,” published by the American Association for the Advancement of Science in 1972, was the first study to research the effects of this famine. Several American researchers went back and looked at medical records of women who were pregnant and had children during this time period or shortly after. The records showed that children born from pregnancies impacted by food rationing had lower birth weights than others born in different areas of the country.
Following these children into their adulthood, researchers found that these children had a higher incidence of obesity, diabetes, and heart disease.
Due to the limited nutritional availability during pregnancy, the researchers claimed these children developed a “thrifty phenotype,” and were “programmed” to deal with the environment they were born into. If the maternal environment sensed there was limited food, the children were programmed to store fat. Once the children grew older, that programming remained, which resulted in the higher tendency towards obesity and metabolic issues.
Additional subsequent research has suggested how alterations to the uterine environment can lead to changes in gene expression or heritable changes known as epi-genetics. Alterations could include: placental development; compromised nutrient transfer to the fetus; hormone or metabolic changes; limited nutrient availability; or stress events.
The “thrifty phenotype” observed in children born from pregnancies during the Dutch Hunger Winter is a real-world example of how environmental factors can change genetic expression. This concept is the core of fetal programming.
Now, animal scientists have begun to realize the possibilities behind this concept and how it could benefit the animal industry. Although there isn’t enough research yet available to make specific management decisions, it’s definitely a concept to pay close attention to in the near future. — Anna Miller, WLJ correspondent
