University of Georgia – Doctoral Candidate – Swine Nutrition
How nutrition can modify the environmental impact of swine production.
One of the major issues facing the swine industry today is the concern of negative environmental impact. In practical swine diets, some particular nutrients are always overfed, which can lead to the increased excretion of nutrients into the environment. Excreted nutrients can affect the environment in a variety of ways. Nutrients that cause the most concern from an environmental standpoint are phosphorus and heavy trace minerals. In our primary swine diet ingredients, corn and soybean meal, around 2/3 of the phosphorus is present in the form of phytic acid (phytate). Phytic acid is the primary phosphorus storage form in the seeds of the plant. Phytic acid is nutritionally unavailable to monogastric animals and can affect the absorption of other nutrients. Phytic acid is negatively charged and will irreversibly bind to other positively charged dietary components, like calcium or zinc. Once bound, these other components are rendered unavailable to the animal, which can negatively impact the growth of the animal and lead to the increased excretion of nutrients into the environment. Supplementing microbial phytase to swine diets has been of recent interest to allow the animal to utilize more phosphorus from feedstuffs, while simultaneously decreasing the amount of phosphorus that is excreted. Phytase is a microbial enzyme, not found in monogastrics, that cleaves phosphate groups from the phytic acid molecule. As an added benefit, phytase can allow better usage of other dietary components and prompts the reduction of other phosphorus sources in the diet, like dicalcium phosphate. As more research is performed and novel microbial phytases are discovered, the reduction of phytase inclusion price can be achieved and can have a positive impact on nutrient utilization and excretion.
Trace mineral excretion is another area in swine nutrition that needs to be improved. It is well known that trace minerals are required in swine diets, but often the mechanisms of absorption and metabolic action are less understood. In recent years, research has shown that increasing the concentration of specific minerals above their recommended levels can have growth-promoting effects. The downside of doing this is that the line is blurred between the concentration that benefits the growth of the animal and the excess concentration that leads to excess mineral excretion. Organic mineral sources have been a major research interest as of late. Organic mineral sources have the ability to increase mineral utilization while decreasing mineral excretion in manure. Organic minerals, in general, consist of a trace mineral element covalently bound to an organic molecule, typically an amino acid. The chemical structure of the organic mineral allows for the mineral to pass through the harsh stomach environment and pass to the small intestine where it can be absorbed with the amino acid it is bound to. Organic minerals and phytase can increase the price of the diet, but if they aid in the absorption and utilization of nutrients, do not negatively impact the growth of the animal, and decrease the concentration of environmentally harmful nutrients, the benefit of inclusion outweighs the cost.
My name is Clint Edmunds; I am 26 years old and am from the small rural town of Bainbridge, Georgia. I am currently in the final year of my Ph.D. program in the Department of Animal and Dairy Science at the University of Georgia. I obtained my Bachelors of Science in Biology from Georgia College and State University (GCSU; May 2017) in Milledgeville, Georgia. I participated in undergraduate research involving interactions of host cellular proteins and adenovirus proteins in vitro. In addition, I was a member of Alpha Tau Omega (Kappa Omega), Tri-Beta (Biological Honor Society), and the Give Center (GCSU Volunteer Organization). I interned at the Georgia Department of Agriculture – Food Safety Division following my graduation from GCSU.
In August of 2017, I started my Master’s Degree at UGA under the direction of C. Robert Dove. My research emphasis during my masters was in mineral nutrition of swine. I successfully defended my thesis, “Evaluation of Trace Mineral Supplementation in Neonatal and Nursery Swine,” in July of 2019. I officially started my Ph.D. program the following month, in the same area of study. The primary project of my Ph.D. involves the evaluation of dietary manganese supplementation on the reproductive performance of sows. A variety of reproductive performance parameters and growth and feed intake data were collected over the course of 10 months and around 9 breeding groups. I have been heavily involved with the Graduate Student Association within the department and the university throughout my time here at UGA. I recently just passed my written and oral qualifying exams and plan to start writing and compiling my dissertation (literature review and manuscripts) in the coming months. My estimated graduation timeline is May 2022.