Pig Pros

Dr. Tami Brown-Brandl

BIOLOGICAL SYSTEMS ENGINEERING

Electronic Sow Feeding Systems: How They Work and What We Can Learn

For this summer internship, the student will investigate three or more commercial Electronic Sow Feeding (ESF) systems to understand how they operate, what data they collect, and how that information can support management decisions. The student will review manufacturer documentation, interview company representatives (with interviews arranged by the research team), and identify common challenges associated with system operation, data access, and interpretation. The project will help establish a foundation for comparing ESF technologies and developing educational resources for producers.

Dr. Samodha Fernando

ANIMAL SCIENCE

Microbial ecology changes during feeding of genetically engineered bacterial strains

With tools for genome engineering and advances in synthetic biology, attempts have been made to engineer better probiotics with desired characteristics and functionalities. Such probiotics with enhanced functional features can be used to improve animal health and productivity as microbes play an important role in nutrient utilization and immune modulation. To date, systematic analysis of feeding genetically engineered microorganisms to livestock and how engineered microbes persist, integrate, and stabilize within the gut microbiome and associated environments in the short and long term has not been performed. The proposed experiments will directly address this knowledge gap by 1) examining ecological changes in the animal's fecal and oral microbiome in response to feeding a genetically engineered organism; 2) evaluate changes in environmental microbiomes associated with soil; 3) evaluate long and short-term stability and persistence of the genetically engineered microbe in the animal gut and gene flow to other microbes; 4) transmission of the genetically engineered microbe between animals. As such, this study will develop critical and timely information to help evaluate the long and short-term risks associated with utilizing genetically engineered microbes in livestock production and will help regulatory agencies make science-based informed decisions on utilizing genetically engineered microbes in livestock production. 

Dr. Jeremy Miles

LIVESTOCK BIO-SYSTEMS RESEARCH UNIT, U.S. MEAT ANIMAL RESEARCH CENTER

Transcriptomic Analysis of Placental, Endometrial, and Umbilical Development in High Prolificacy Swine

This project is part of an ongoing research effort investigating how maternal dietary supplementation with glucosamine or a phytogenic blend influences fetal development in pigs with exceptionally large litters (high uterine capacity). Previous work in our group has shown that these feed additives in gestational diets alter microstructural features of the placenta and umbilical cord in divergent‑sized littermates. Building on these findings, the next step is to determine how these structural changes relate to gene expression patterns in the uterine endometrium, placenta, and umbilical cord.  The objective of this project is to determine if glucosamine and phytogenic dietary supplements influence the transcriptomic landscape of maternal–fetal tissues in high‑prolificacy pregnancies, and if these molecular changes help explain variation in placental structure and fetal growth.  The intern will work closely with USDA-ARS scientists and technicians to assist in sample processing and preparation for Illumina RNA‑sequencing (RNA‑seq).  Student activities may include RNA extraction, RNA quality assessment, cDNA library preparation, and involvement in sequencing workflows.  The student may also participate in downstream bioinformatic steps such as alignment and differential gene expression analysis. Through this internship, the student will gain hands‑on training in modern molecular biology, transcriptomics, and computational data analysis, as well as exposure to research on maternal–fetal physiology, placental biology, and swine reproductive performance.

Dr. William Oliver

NUTRITION, GROWTH AND PHYSIOLOGY RESEARCH UNIT, U.S. MEAT ANIMAL RESEARCH CENTER

The use of supplemental dextrose in late gestation sow diets

We hypothesize that supplemental dextrose during gestation will improve piglet mitochondrial efficiency, thus leading to improved overall feed efficiency throughout the production cycle. Forty multiparous sows will be fed either a control, or control + 5% dextrose diet (n=20/treatment) for the last third of gestation. Growth and feed intake of offspring will be determined throughout the production cycle.  Blood from both sows and offspring will be analyzed for glucose, insulin, plasma urea nitrogen, and non-esterified fatty acids. At two timepoints, offspring from each litter will be euthanized and the soleus and gastrocnemius muscle extracted for analysis of mitochondrial function.  Interns can expect to participate in animal husbandry, blood collection and laboratory analyses, muscle sample collection, and mitochondrial analyses.  In addition, scientists across USMARC will have experiments ongoing and there will be opportunities to participate in experiments in multiple disciplines

Dr. Lea Rempel

LIVESTOCK BIO-SYSTEMS RESEARCH UNIT, U.S. MEAT ANIMAL RESEARCH CENTER

Impact of hypo- or hyper-methylating diets during early placental establishment on  placental gene expression at 46- and 107- days gestation

This project investigates how diets that promote either hypo or hyper methylation during early pregnancy influence placental and fetal development in pigs. Because previous work showed seasonal differences in placental DNA methylation markers (5mC and 5hmC), this study evaluated whether altering methylation through diet from days 5–30 of gestation affects developmental outcomes at mid gestation (day 46) and late gestation (day 107). Gilts received either a control diet, a phytogenic blend to encourage hypomethylation, or methionine to promote hypermethylation. Researchers recorded uterine measurements, fetal survival, and placental traits. Diet and season interacted to influence several outcomes, particularly at day 107, where methionine supplementation during summer produced fetal and placental traits resembling those typically seen in winter pregnancies.

As a complementary molecular project, placental samples can be analyzed using RT² PCR Arrays targeting select chromatin modification genes. This work would quantify expression of DNA methyltransferases, demethylases, and histone modifying enzymes, previously shown to be influenced by season of breeding (winter or summer), to determine whether early gestation dietary treatments shift epigenetic regulatory pathways. Integrating these gene expression data with morphological findings will help clarify how nutrient driven methylation environments shape placental function and fetal growth.

Dr. Brett White

ANIMAL SCIENCE

Determining how gonadotropin-releasing hormone 2 (GnRH-2) and its receptor impact swine reproduction.

Infertility is a huge problem in the swine industry, limiting the profits of producers. In addition, pigs serve as an excellent biomedical model for infertility in humans. Our lab is interested in methods to solve fertility issues. We are investigating the biological mechanisms underlying how a hormone (GnRH-2) and its interacting partner (GnRH-2 receptor) influence reproduction.  To accomplish this, we utilize a genetically engineered pig line in which this important mechanism has been disrupted. This is a newly identified system, so every research result obtained is highly impactful. More importantly, though, these pigs also express a green fluorescent protein.  So, we get the opportunity to study pigs that actually glow-in-the-dark!

Potential activities and skills to be obtained include hands-on swine experience in care/handling (feeding, injections, piglet processing, weaning), reproductive management (detection of estrus, boar collection, artificial insemination, farrowing) and assisting with experiments (surgery, blood draws, tissue collection). Furthermore, students will be exposed to general laboratory procedures (preparing buffers/media, conducting experiments, analyzing data) as well as molecular biology techniques (DNA/RNA/protein isolation, genetic screening, PCR, western blotting, immunohistochemistry, quantification of hormones). Students will keep a thorough lab notebook, attend weekly lab meetings and present their progress twice during the summer.