Fetal Programming Explores Performance Opportunities

Researchers continue to explore how nutrition during gestation affects fetal development, producer profitability, and the industry’s end product.

Beef producers have been especially encouraged to watch body condition as cows experience their third trimester of pregnancy, when 75% of fetal growth occurs. Interesting research, though, is revealing that a watchful eye on nutrition and body condition may be warranted during early and mid gestation too.

This research that is getting a lot of focus is known as fetal programming. It refers to a maternal stimulus or stress at a critical period in fetal development that can have long-term impacts on the offspring later in life. These impacts can be due to nutrition, as well as environmental and hormonal stresses.

While this research is relatively new within production livestock, the concept is not new itself. A researcher from England, who coined the term, developed his theory through the use of human epidemiological data. It unveiled that when fetuses were exposed to nutrition, disease, and/or stress during critical times of early development, long-term effects could be seen on their development, growth, and disease risk.

This researcher, Dr. David Barker at Southampton University in England, and his colleagues determined that maternal undernutrition in the first half of gestation, followed by adequate nutrition from mid-gestation to term, resulted in infants that were of normal birth weight but were, proportionally, longer and thinner. This early fetal undernutrition resulted in an increased incidence of health problems experienced by these individuals as adults, including obesity, diabetes, and cardiovascular disease.

Animal agriculture has more slowly embraced the concept to improve animal growth, development, and well-being through fetal programming studies. At “Fetal Programming in Animal Agriculture,” the joint annual meeting of the American Society of Animal Science, the American Dairy Science Association, and the Canadian Society of Animal Science, held in Montreal in 2009, a team of researchers told participants, “The ability to improve animal production and well-being by altering the maternal environment holds enormous challenges and great opportunities for researchers and animal industries.”

This symposium provided a forum to overview the current knowledge of fetal programming in relation to animal sciences. It emphasized muscle tissue, milk supply, and reproduction across agriculturally important species.

Promises of increased performance

Ongoing fetal research studies involve humans and beef cattle to sheep and rats, but no actual conclusions can yet be drawn. Beef cattle studies do point to several potential trends indicating that management and nutrition of the cow during gestation influences the profitability of her calf.

A collaborative study between the University of Wyoming and USDA’s Ft. Keogh Livestock and Range Laboratory in Montana was conducted on spring-born steer calves whose mothers had grazed native range vs. improved pastures during mid-gestation (late-summer or fall), both groups without supplementation.

Calves were backgrounded, entered the feedlot at similar weights, and data collected at 120 days. The steers from dams that grazed native range (lower-quality forage) posted lower gains, lighter carcass weights, less backfat, and lower marbling scores.

The University of Nebraska has carried out studies, focusing on the impact of protein supplementation in late gestation. Their work suggests that the dam’s nutrition during pregnancy probably has a large effect on her calf, and that additional supplementation is of benefit to calf health, weaning weights, finished weights, and the potential for achieving a USDA quality grade of Choice or better.

UNL research also suggests that dam nutrition affects heifer fertility. Replacement females from supplemented dams posted higher pregnancy rates and more of these heifers calved earlier in the calving season.

While these studies have focused on late gestation, other research has indicated the first two-thirds of gestation are important too. A team of South Dakota State University researchers are studying how second-trimester nutrition affects subsequent calf health, growth, performance, and meat quality, all information that producers can use.