Robert G. Elkin
- Ph.D., Nutritional Biochemistry, Purdue University (1981)
- M.S., Nonruminant Nutrition, Purdue University (1977)
- B.S., Animal Science (with distinction), The Pennsylvania State University (1975)
- Professor of Avian Nutritional Biochemistry, Department of Animal Science, The Pennsylvania State University, 2012-present
- Professor of Poultry Science and Head, Department of Poultry Science, The Pennsylvania State University, 1999-2012
- Professor of Animal Sciences, Purdue University, 1999
- Associate Professor of Animal Sciences, Purdue University, 1986-99
- Assistant Professor of Animal Sciences, Purdue University, 1981-86
Program Objectives and Accomplishments
The research program centers on modification of avian cholesterol and lipoprotein metabolism, with an overall goal of producing table eggs with markedly reduced cholesterol and fat contents. Another area of interest is amino acid nutrition and metabolism of poultry. Recent work has primarily focused on (1) the pharmacological manipulation of egg cholesterol content and (2) lipid and lipoprotein metabolism in the restricted ovulator ( RO ) chicken, a unique subpopulation of nonlaying White Leghorn chickens with hereditable hyperlipidemia and aortic atherosclerosis (Elkin et al., 2003b).
We have demonstrated that several inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR), popularly known as "statins", are effective egg cholesterol-lowering agents when orally administered to laying hens (for reviews see Elkin, 2006, 2007). HMGR is the key enzyme that controls the rate of cholesterol biosynthesis in the liver. Of the many compounds tested, atorvastatin (Lipitor Ò ) was the most effective and reduced egg cholesterol contents by almost 50% (Elkin et al., 1999). Although atorvastatin also caused favorable changes (from a human nutrition standpoint) in egg protein/amino acid and lipid contents, some [ 14 C] residue was found in egg yolks from hens administered a single oral dose of [ 14 C] atorvastatin (Elkin et al., 2003a). As a result, we have turned our attention toward the evaluation of a variety of "GRAS" (generally regarded as safe) substances and natural products for egg cholesterol modification.
Sexually mature RO female chickens, first described as a non-laying strain, exhibit endogenous hyperlipidemia and develop atherosclerotic lesions as a result of a hereditable point mutation in the oocyte very low density lipoprotein (VLDL) receptor. In a recent 20-d study (Elkin et al., 2006), RO hens and their normolipidemic (NL) siblings were fed either a control diet, or the control diet supplemented with 0.06% atorvastatin. Compared to NL hens, RO birds exhibited greatly elevated baseline plasma total cholesterol and triglyceride concentrations, which were markedly attenuated by atorvastatin. Messenger RNA levels of several key genes involved in hepatic VLDL assembly were suppressed in RO vs. NL hens, but were unaffected by atorvastatin treatment. In contrast, atorvastatin elevated liver HMGR mRNA levels in NL and RO birds, but only NL hens exhibited an atorvastatin-associated increase in hepatic HMGR immunoreactive protein levels. Down-regulation of HMGR gene expression due to higher baseline levels of circulating cholesterol may explain why RO birds responded less robustly than NL hens to orally administered atorvastatin.
Besides being a useful model for studying lipoprotein metabolism and atherosclerosis, nonlaying mutant RO hens have recently been utilized in investigations centered on endocrine dysfunction (Ocón et al., 2007), bone metabolism (Kim et al., 2004), and the etiology of ovarian cancer (Giles et al., 2010).
Refereed Journal Articles (1997-present; 62 total)
Giles, J. R., R. G. Elkin, L. S. Trevino, M. E. Urick, R. Ramachandran and P. A. Johnson. 2010. The restricted ovulator chicken: A unique animal model for investigating the etiology of ovarian cancer. Int. J. Gynecol. Cancer 20:738-744.
Elkin, R. G. 2009. Editorial: Additional perspectives on analytical techniques and standardization: Cholesterol and fatty acid contents of eggs, tissues, and organs. Poultry Sci . 88:249-250.
Elkin, R. G. and E. S. Lorenz. 2009. Feeding laying hens a bioavailable soy sterol mixture fails to enrich their eggs with phytosterols or elicit egg yolk compositional changes. Poultry Sci . 88:152-158.
Ocón, O. M., S. Maddineni, G. L. Hendricks III, R. G. Elkin, J. A. Proudman and R. Ramachandran. 2007. Pituitary progesterone receptor expression and plasma gonadotrophin concentrations in the reproductively dysfunctional mutant restricted ovulator chicken. Dom. Anim. Endocrinol . 32:201-215.
Elkin, R. G. 2007. Reducing shell egg cholesterol content. II. Review of approaches utilizing non-nutritive dietary factors or pharmacological agents and an examination of emerging strategies. World's Poultry Sci. J. 63:5-31.
Elkin, R. G. 2006. Reducing shell egg cholesterol content. I. Overview, genetic approaches, and nutritional strategies. World's Poultry Sci. J. 62:665-687.
Elkin, R. G., Y. Zhong, S. S. Donkin, E. Hengstschläger-Ottnad and W. J. Schneider. 2006. Effects of atorvastatin on lipid metabolism in normolipidemic and hereditary hyperlipidemic, non-laying hens. Comp. Biochem. Physiol. 143B:319-329.
Kim, W. K., B. C. Ford, A. D. Mitchell, R. G. Elkin and R. M. Leach, Jr. 2004. Comparative assessment of bone among wild-type, restricted ovulator, and out-of-production hens. Br. Poultry Sci. 45:463-470.
Elkin, R. G., E. J. Furumoto and C. R. Thomas. 2003a. Assessment of egg nutrient compositional traits and residue in eggs, tissues, and excreta following oral administration of atorvastatin to laying hens. J. Agric. Food Chem. 51:3473-3481.
Elkin, R. G., Y. Zhong, R. E. Porter and R. L. Walzem. 2003b. Validation of a modified PCR-based method for identifying mutant restricted ovulator chickens: Substantiation of genotypic classification by phenotypic traits. Poultry Sci. 82:517-525.
Elkin, R. G. and Y. Zhong. 2002. Assessment of reproductive function in mutant restricted ovulator carrier roosters. Poultry Sci. 81:1280-1282.
Elkin, R. G, E. Arthur, B. R. Hamaker, J. D. Axtell, M. W. Douglas and C. M. Parsons. 2002. Nutritional value of a highly digestible sorghum cultivar for meat-type chickens. J. Agric. Food Chem. 50:4146-4150.
Ragland, D., C. R. Thomas, R. G. Elkin, D. Schafer and O. Adeola. 1999. The influence of cecectomy on metabolizable energy and amino acid digestibility of select feedstuffs for White Pekin ducks. Poultry Sci . 78:707-713.
Elkin, R. G., Z. Yan, Y. Zhong, S. S. Donkin, K. K. Buhman, J. A. Story, J. J. Turek, R. E. Porter, Jr., M. Anderson, R. Homan and R. S. Newton. 1999. Select 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors vary in their ability to reduce egg yolk cholesterol levels in laying hens through alteration of hepatic cholesterol biosynthesis and plasma VLDL composition. J. Nutr. 129:1010-1019.
Elkin, R. G. and Z. Yan. 1999. Relationship between inhibition of mevalonate biosynthesis and reduced fertility in laying hens. J. Repro. Fertil. 116:269-275.
Elkin, R. G. and Z. Yan. 1997. Uptake of yolk very low density lipoprotein by chicken and quail embryos is not mediated by a homologue of the oocyte vitellogenesis receptor. Comp. Biochem. Physiol. 118B:913-920.
Recent Published Conference Proceedings Papers
Elkin, R. G. and D. J. Burns. 2007. Lack of effect of dietary policosanol on laying hen performance and egg composition. Proceedings of the XVIII European Symposium on the Quality of Poultry Meat and the XII European Symposium on the Quality of Eggs and Egg Products, September 2-5, 2007, Prague, Czech Republic, pp. 225-227.
Elkin, R. G. 2006. Reducing cholesterol levels in eggs. Proceedings of the Functional Foods Conference: Emerging Markets for Livestock, June 27-28, Stratford, Ontario, Canada, pp. 117-122.
Elkin, R. G. 2005. Challenges and opportunities in laying hen nutrition in the 21 st century. Proceedings of the 12 th International Symposium on Animal Nutrition, Pannon Agricultural University, Kaposvár, Hungary, pp. 67-90.
Elkin, R. G. 2005. Ovo-nutriceuticals and egg-derived biomedical products: opportunities and challenges. Proceedings of the North Atlantic Poultry Health & Management Conference, May 10-11, Windsor Locks, CT. 13 pp.
United States Patent No. 6,177,121 B1: “Composition and method for producing low-cholesterol eggs”, Awarded January 23, 2001.
Awards and Honors
Pioneer of the Mid-Atlantic Nutrition Conference, 2008.
American Feed Industry Association Nutrition Research Award, Poultry Science Association, 1997.
Organization for Economic Cooperation and Development Research Fellowship (Austria), 1995.
Visiting Professor, Tokyo University of Agriculture and Technology (Japan), 1994.
Fulbright Scholar Research Award (Austria), 1992-93.
American Egg Board Research Award, Poultry Science Association, 1991.
W. R. Featherston Award (Outstanding Graduate Student in Animal Sciences), Purdue University Department of Animal Sciences, 1981.
Research Fellowship in Poultry Science, Ralston Purina Company (St. Louis, MO), 1979-80.
David Ross Fellowship, Purdue Research Foundation, 1978-79.
Certificate of Excellence, Poultry Science Association, 1977.
Hubbard Graduate Award, Hubbard Farms (Walpole, NH), 1977.
Memberships in Academic, Professional, and Scholarly Societies
- American Association for the Advancement of Science
- American Chemical Society, Agricultural and Food Chemistry Division
- American Society for Nutrition (formerly American Institute of Nutrition)
- Gamma Sigma Delta
- Poultry Science Association
- World's Poultry Science Association, USA Branch
|Purdue||ANSC 221||Spring, 1979||Principles of Animal Nutrition|
|Purdue||ANSC 501||Spring, 1982||Laboratory Techniques in Animal Sciences|
|Purdue||ANSC 501||Spring, 1983||Laboratory Techniques in Animal Sciences|
|Purdue||ANSC 501||Spring, 1984||Laboratory Techniques in Animal Sciences|
|Purdue||ANSC 501||Spring, 1985||Laboratory Techniques in Animal Sciences|
|Purdue||ANSC 682||Fall, 1985||Animal Nutrition Seminar|
|Purdue||ANSC 501||Spring, 1986||Laboratory Techniques in Animal Sciences|
|Purdue||ANSC 501||Spring, 1987||Laboratory Techniques in Animal Sciences|
|Purdue||ANSC 501||Spring, 1988||Laboratory Techniques in Animal Sciences|
|Purdue||ANSC 682||Fall, 1988||Animal Nutrition Seminar|
|Purdue||ANSC 501||Spring, 1989||Laboratory Techniques in Animal Sciences|
|Purdue||ANSC 595B||Spring, 1992||Natural Toxicants in Feedstuffs|
|Purdue||AGR 497||Summer, 1994||Corporate Internship Program|
|Purdue||AGR 493E||Fall, 1994||Corporate Culture in Japan|
|Purdue||ANSC 682||Fall, 1994||Animal Nutrition Seminar|
|Purdue||ANSC 691||Spring, 1995||Special Topics (Natural Toxicants in Feeds)|
|Purdue||ANSC 595B||Spring, 1996||Natural Toxicants in Feedstuffs|
|Purdue||ANSC 595B||Spring, 1997||Natural Toxicants in Feedstuffs|
|Purdue||ANSC 522||Fall, 1997||Monogastric Nutrition|
|Purdue||ANSC 525||Spring, 1998||Natural Toxicants in Feedstuffs|
|Purdue||ANSC 522||Fall, 1998||Monogastric Nutrition|
|Purdue||ANSC 525||Spring, 1999||Natural Toxicants in Feedstuffs|
|Penn State||ANSC 301||Fall, 2003||Principles of Animal Nutrition (co-taught with R. S. Kensinger)|
|Penn State||ANSC 497A||Spring, 2010||Poultry Science Study Tour to the Netherlands (co-taught with R. M. Hulet)|
ANSC 501 (Laboratory Techniques in Animal Sciences) was a 3-credit course designed for beginning graduate/advanced undergraduate students and covered both theoretical and applied aspects of analytical procedures employed in animal sciences. Techniques discussed and performed included spectrophotometry, atomic absorption spectrophotometry, fluorometry, use of radioisotopes, radioimmunoassay, high performance liquid chromatography, gas chromatography, affinity chromatography, ion exchange chromatography, thin layer chromatography, gel permeation chromatography, and electrophoresis.
ANSC 522 (Monogastric Nutrition) was a 3-credit course that encompassed nutrient digestion and absorption, metabolism, utilization, and interrelationships in poultry, swine, and other monogastric animals. Weekly discussion of a current journal article both reinforced concepts presented in lecture and allowed for the introduction of additional relevant information.
ANSC 525 (Natural Toxicants in Feedstuffs) was a 2-credit course which provided an overall view of the significance of plant toxicants in domestic animal production. Emphasis was placed on the chemical nature and occurrence of toxicants, their metabolism in livestock and poultry, and the pathological effects that they produce. Over 300 slides depicting various poisonous plants and/or associated toxicoses in domestic animals were shown in class, while reading assignments and current journal articles supplemented the lecture material.
ANSC 301 (Principles of Animal Nutrition) is a 3-credit course that covers nutrients and their metabolism, the nutritional requirements of animals, the nutritional value of various feeds, and principles of ration formulation.
ANSC 497A (Poultry Science Study Tour to the Netherlands) was a 2-credit course with an embedded 8-day international experience. The objectives of the course were three-fold:
- to enhance student understanding of global poultry production systems
- to increase student awareness of key issues facing the poultry industries of the European Union
- to introduce students to the culture of the Netherlands.
Service to the Profession
Poultry Science Association
- Metabolism & Nutrition Co-Section Editor of Poultry Science , 1995-99, 2005-11
- Associate Editor of Poultry Science , Metabolism & Nutrition Section, 1985-90; 1994-95; 2001-03
- Editorial/Review Board of Journal of Applied Poultry Research , 2006-2007
- American Feed Industry Association Nutrition Research Award Committee, 1998-00; Chairman, 2000.
- American Egg Board Technical Committee, 1993-96; Chairman, 1996
- Ancillary Scientist Committee, 2001-04
- Alltech Student Research Manuscript Award Committee, 1987-90, 2001-04; Chairman, 1988, 1989
- Long Range Planning Committee, 1989-90
- Association Representative to the Ralston Purina Research Fellowship Award Committee, 1986-88; Chairman, 1988.
World's Poultry Science Association-USA Branch
- Board of Directors, 2002-06
- Chair, Youth Committee, 2003-04
Ad hoc reviewer of manuscripts for the following journals:
- African Journal of Biotechnology
- Analytical Biochemistry
- Animal Feed Science and Technology
- Biochimistry et Biophysica Acta
- Biological and Trace Element Research
- British Journal of Nutrition
- British Poultry Science
- Comparative Biochemistry and Physiology
- Growth, Development and Aging
- Journal of Agricultural and Food Chemistry
- Journal of Agricultural and Food Science
- Journal of Applied Poultry Research
- Journal of Applied Psychology
- Journal of Experimental Biology
- Journal of Food Science
- Journal of Nutrition
- Journal of Nutritional Biochemistry
- Journal of the Association of Official Analytical Chemists International
- Livestock Science
- Molecular and Cellular Endocrinology
- Neuroscience and Biobehavioral Reviews
- Physiology and Behavior
- Proceedings of the Society for Experimental Biology and Medicine
- South African Journal of Animal Science
- Turkish Journal of Veterinary and Animal Sciences.
Ad hoc reviewer of proposals sent to the USDA National Research Initiative Competitive Grants Program, 1991-present; ad hoc reviewer of four proposals sent to the USDA Small Business Innovation Research Program, 1999-present; ad hoc reviewer of one proposal sent to the NSF, Integrative Animal Biology Program, 1995.
Mid-Atlantic Nutrition Conference (former Maryland Nutrition Conference), General Session Chair, 2007; Poultry Nutrition Committee, 2010, 2011.
of Animal Science Societies (FASS)-American Feed Industry Association
New Frontiers in Animal Nutrition Award Committee, 2005.
Appointed by the Dean of the Faculty of Agriculture, Swedish University of Agricultural Sciences (Uppsala, Sweden) to serve as the "Opponent" (External Examiner) at Bui Xuan Men's public defense of his Ph.D. Thesis on November 15, 2001.
Organized and chaired the American Institute of Nutrition’s 61st Annual Poultry Nutrition Conference, “Avian Lipoprotein Metabolism: An Update”, Experimental Biology ‘96 Meeting, April 14, 1996, Washington, DC. Served as guest editor of the proceedings papers, which were published in the Journal of Nutrition .
Invited participant in a USDA-sponsored Roundtable Discussion of Cholesterol Levels in Poultry, Hyattsville, MD, January 28, 1994.
Ad hoc reviewer of 25 Fulbright Senior Scholar Program proposals as member of the Life Sciences C - Biochemistry Specialist Review Committee, Council for International Exchange of Scholars, 1999, 2000.
Fulbright Selection Committee (Vienna, Austria). Interviewed Austrian applicants for 1993-94 Fulbright Grants, 1992-93.Nutrition Committee member for the Food Animal Research Symposium, Lexington, KY, November 2-4, 1986.