Experts in human health have long known that the mother’s nutrition during pregnancy can positively or negatively affect the long-term health of her baby. Many of the interactions, however, are not well understood and remain under study. Similar influences occur in cattle, but again, many questions remain as to critical nutrients, critical times during gestation and the outcomes in terms of animal health, performance and beef quality.
During the recent Beef Improvement Federation (BIF) conference in Lincoln, Neb., North Dakota State University animal scientist Kim Vonnahme, PhD, outlined ongoing research into “developmental programming” in cattle. People have used the term “fetal programming,” but Vonnahme says developmental programming is a more accurate term, as nutrition during gestation can affect development of the placenta and other organs, which in turn affect development of the fetus.
Vonnahme notes that with steers typically going to slaughter at less than 30 months of age, they spend more than 30 percent of their lives inside their dam’s uterus, being nourished by the placenta. At critical times during those nine months of gestation, a stimulus or insult related to the dam’s nutrition can establish a permanent response.
Some complications related to the dam’s nutrition reported in livestock include increased neonatal morbidities and mortalities, intestinal and respiratory dysfunctions, slow postnatal growth, increased
fat deposition, differing muscle fiber diameters and reduced meat quality.
In her presentation, Vonnahme outlined some of her laboratory’s investigations on how maternal environment can impact fetal and placental development, impacts on uterine and/or umbilical blood flow in cattle and sheep, and potential timing to increase uteroplacental blood flow.
Key findings from her research and others include:
- In cows gestated on range, where crude protein of forage is less than 6 percent, those that were protein supplemented during late gestation had calves similar in birth weight, with increased weaning weight compared to protein unsupplemented cows. It is important to note, she says, that the protein supplementation enhanced growth after birth.
- Pregnancy rates in heifer calves born from protein supplemented cows were enhanced compared to control cows.
- Nutrient restriction during mid-gestation is associated with similar birth weights but reduced weaning weights, reduced carcass weights and decreased beef tenderness in offspring, compared with those from dams without nutrient restriction during the same period.
- Protein supplementation for cows on winter range during late pregnancy affects steer performance, but the same effect was not seen in steers from dams wintered on corn stalks. In both groups though, protein supplementation during late pregnancy positively affected carcass quality in the steers.
- Early calving and pregnancy rates in heifers improved in groups from supplemented dams.
Vonnahme and her team currently are using Doppler ultrasound scanning to monitor the effects of the dam’s diet on blood flow in the placenta, trying to identify effects at different stages of placental development and fetal development. They hope to improve approaches to management of livestock during pregnancy which may impact not only that dam’s reproductive success, but her offspring’s growth potential and performance later in life.
The Power Point slides, audio recording and proceedings paper from Neibergs’ presentation are available at the BIF Conference website.