Physiology Symposium Highlights
By Kaitlyn Sommer
Nutritional Advances in fetal and neonatal development: Introduction to Current Knowledge
The Nutritional Advances in fetal and neonatal development seminar began with an introduction to current knowledge by Joel Caton from North Dakota State University. Dr. Caton spoke about how the insult or change during a developmental window can be lasting for production and growth, something that, as he stated, is not a new concept for animal and biomedical scientists. Things such as obesity, metabolic diseases, and cancer can all be set up while in utero. Another major component to brought to light by Dr. Caton is that production efficiency is most likely programmed in utero. This is shown in how a mother’s inappropriate supply can result in different outcomes for the offspring that can then persist into the offspring’s adulthood. Fetuses are not just affected by nutritional deficiencies but also by high inclusions; these can affect both the tissues and organs of the offspring in a negative manner. Maternal, therefore, fetal nutrition is critical for the fetus survival and development. Dr. Caton’s take home message is that “What mom eats matters” because this can have a major impact on the fetus’s outcomes.
Nutritional Advances in Fetal and Neonatal Development: Stage of Gestation and Placental Nutrient Supply
Dr. Caleb Lemley from Mississippi State University talked above Stages of Gestation and Placental Nutrient Supply. Dr. Lemley looked to see how a low-input diet vs. conventional forage affected the fetus. His results showed that the fetal weight relative to the uterine artery was decreased in the restricted (low-input) treatment. This was also shown in regards to Brahman vs. Angus, where the Brahman had a decrease in fetal weight relative to the uterine artery. This lead Dr. Lemley to conclude that the restricted group had an increased efficiency in fetus growth. Dr. Lemley also studied the effect of melatonin supplemented at a level of 20 mg per day during the last third of the heifer’s gestation. Calves born from mothers that had supplemented melatonin had a higher weaning weight than those that were not supplemented but did not have a higher birth weight. Dr. Lemley concluded that the placental nutrient supply could be affected by the mother’s nutrient restriction. This restriction causes a decrease in the uterine artery blood flow leading to a compensatory response in the cotyledon of the placenta, affecting fetal growth pending the stage of utero in which this occurs. Where the mothers supplemented with melatonin leads to an increase in the caruncles, decreasing the angiogenesis on the placentas cotyledons causing similar birth weights between the melatonin and control heifers.
Nutritional Advances in Fetal and Neonatal Development: AA supplementation
Dr. Kendall Swanson from North Dakota State University looked at supplementation of amino acids in fetal and neonatal development. When looking at just control and restricted diet in ewes, Dr Swanson showed how there is a major difference between the total amino acid flux in pregnant ewes; this research showed that the fetuses were lighter at the time of birth. Dr. Swanson talked about four important amino acids that can cause major effects in neonatal and fetal development; these are Glutamine, tryptophan, leucine, and arginine. Mentioning that in early work, lambs that were on a restricted diet but had supplemented arginine had higher birth weights than lambs that were just on restricted feed. This and other research lead Dr. Swanson to conclude that if feed is restricted, the animals may become more efficient at utilizing the different amino acids.
Nutritional Advances in Fetal and Neonatal Development: Methyl Donors
Dr. Fernanada Batistel from Utah State University looked at Methyl Donors in fetal and neonatal development. She specifically discussed the effects of 2 nutrients being methionine and choline being added during late gestation or early life, respectively. Her research showed that methionine supplied during late gestation causes an increase in dry matter intake, blood glucose, and the total amino acid concentration. Her results also showed that methionine causes an increase in calf body weight, and the placenta had an increase in glucose transporters and an increase of enzymes present in the Citric Acid Cycle. Dr. Batistel stated that “overall there is an impact in placenta metabolism and growth of offspring. But it isn’t clear in this is a direct or indirect effect of supplemented methionine.” As stated before, she also looked into choline added in early life. Her research concluded that the overall choline added during the end of gestation causes an enhance in offspring growth and performance. With her take home message being “Methyl donor supply seems to affect dam and offspring metabolism, but the mechanism used is not understood.”
Nutritional Advances in Fetal and Neonatal Development: Effect of FA Supplementation
Dr. Alejandro Relling from Ohio State University looked at the effect of fatty acid supplementation. His studies specifically look at the diet inclusion of MUFA (saturated fat) versus PUFA (polyunsaturated fat) during ewes late gestation. His results showed that when PUFA was added to the diet at a 1 or 2% inclusion rate, the dams had an increase in final body weight. The 2% PUFA including caused an increase in average daily gain (ADG). Dr. Relling also spoke about how other species have shown responses to PUFA added diets. Dairy cattle that had less than 1.8% dry matter intake (DMI) of PUFA’s tended to have offspring that had an increase of 10 to 20% milk yield at first lactation. Beef cattle showed an increase in marbling, REA, and body weight. Lastly, sheep had an increase in body weight of 3-5%. Dr. Relling also looked at MUFA and PUFA addition to diets during gestation in lambs. This resulted in larger offspring came from dams’ that were fed the MUFA diet but then switched to the PUFA diet for the finishing stage. Lambs that were born from dams on the MUFA diet also tended to have a higher ADG and DMI, along with higher concentrations of glucose and insulin than the PUFA diets. Dr. Relling’s research shows that physiological changes due occur when PUFA are added to the diet during late and early gestation.
Nutritional Advances in Fetal and Neonatal Development: Mineral Nutrition
Dr. Allison Meyer from the University of Missouri presented on Mineral Nutrition for fetal and neonatal development. She started by talking about how the maternal environment has an effect on offspring development and that this effect does not stop once the offspring is born, the environment still effects the offspring’s development. Dr. Meyer Focused on trace minerals, “things that have been known for years to be important during gestation.” During late gestation, the fetus continues to grow along with minerals being accumulated within it. Dr. Meyer’s study showed that adequate selenium levels given to dams caused a reduced birth weight, while high selenium improved birth weight. Dr. Meyer also looked at the perinatal and postnatal time period. During the perinatal period, if extra copped was supplemented to the diet, than there was a higher enzyme activity for things such as cytochrome C oxidase in the electron transport chain. Dr. Meyer ended her talk stayin that “ There are some thoughts that there is a higher requirement for minerals than currently believed.”