Robert G. Elkin
Professor of Avian Nutritional Biochemistry
- 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, fatty acid, and lipoprotein metabolism, with an overall goal of producing table eggs with markedly reduced cholesterol and fat contents and/or altered fatty acid contents that promote human health. Another area of interest is amino acid nutrition and metabolism of poultry. Work over the past two decades has primarily focused on: (1) reduction of egg cholesterol content using orally administered pharmacological agents or natural products; 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 (for review, see Elkin et al., 2012). More recent studies, in conjunction with K. J. Harvatine, have been centered on evaluating novel, non-marine dietary sources of long-chain omega-3 fatty acids to enrich hens’ eggs (Elkin et al., 2015) and broiler meat with heart healthy very-long chain omega 3 fatty acids (eicosapentaenoic acid and docosahexaenoic acid) (Elkin et al., 2016).
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) 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 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; 67 total)
Elkin, R. G., Y. Ying, Y. Fan, and K. J. Harvatine. 2016. Influence of feeding stearidonic acid (18:4n-3)-enriched soybean oil, as compared to conventional soybean oil, on tissue deposition of very long-chain omega-3 fatty acids in meat-type chickens. Anim. Feed Sci. Technol. 217:1-12.
Elkin, R. G., Y. Ying, and K. J. Harvatine. 2015. Feeding laying hens stearidonic acid-enriched soybean oil, as compared to flaxsed oil, more efficiently enriches eggs with very long-chain n-3 polyunsaturated fatty acids. J. Agric. Food Chem. 63:2789-2797.
Tiwari, A., J. A. Hadley, G. L. Hendricks 3rd, R. G. Elkin, T. Cooper and R. Ramachandran. 2013. Characterization of ascites-derived ovarian tumor cells from spontaneously occurring ovarian tumors of the chicken: evidence for E-cadherin upregulation. PLoS One 8:e57582.
Elkin, R. G., R. Bauer, and W. J. Schneider. 2012. The restricted ovulator chicken strain: an oviparous vertebrate model of reproductive dysfunction caused by a gene defect affecting an oocyte-specific receptor. Anim. Reprod. Sci. 136:1-13.
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.
Elkin, R. G. 2017. Cholesterol in chicken eggs: Still a dietary concern for some. Chapter 18 in: Egg Innovations and Strategies for Improvements (P. Y. Hester, Ed.), Academic Press: Oxford, U.K., pp. 189-198.
Elkin, R. G. 2017. Influence of plant toxins on laying hen performance and egg quality. Chapter 47 in: Egg Innovations and Strategies for Improvements (P. Y. Hester, Ed.), Academic Press: Oxford, U.K., pp. 499-512.
Elkin, R. G. 2002. Nutritional components of feedstuffs: A qualitative chemical appraisal of protein. Chapter 4 in: Poultry Feedstuffs: Supply, Composition, and Nutritive Value. Poultry Science Symposium Series, vol. 26 (J. M. McNab and K. N. Boorman, Eds.), CABI Publishing: Wallingford, Oxon, U.K., pp. 57-86.
Vieira, A., R. G. Elkin and K. Kuchler. 1994. Western blotting and ligand blotting using enhanced chemiluminescence (ECL) and radio-iodine detection. Part 7/Section C in: Cell Biology: A Laboratory Handbook, vol. 2 (J. E. Celis, Ed.), Academic Press: New York, pp. 314-321.
Select 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)|
|Penn State||ANSC 590||Fall, 2012||Colloquium - (co-taught with A. N. Hristov)|
|Penn State||ANSC 590||Fall, 2013||Colloquium - (co-taught with W. Liu)|
|Penn State||ANSC 499A||Spring, 2014||German Poultry Industry Study Tour - (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: (1) To enhance student understanding of global poultry production systems; (2) To increase student awareness of key issues facing the poultry industries of the European Union; and (3) To introduce students to the culture of the Netherlands.
ANSC 590 (Colloquium) is a 1-credit graduate course that requires each student to deliver an oral presentation at an advanced level on a topic that is relevant to their research area. A written abstract is also required. The goals of the course are to help students to develop skills for scientific presentations, to sharpen speaking capacities in a public forum, and to help students to improve their scientific writing abilities. Students are also encouraged to participate in post-presentation discussions.
ANSC 499A (German Poultry Industry Study Tour) is a 2-credit course with an embedded 8-day international experience. The objectives of the course are three-fold: (1) To enhance student understanding of global poultry production systems; (2) To increase student awareness of key issues facing the poultry industries of Germany and the European Union; and (3) To introduce students to German culture, food, and history.
Service to the Profession
Poultry Science Association
- Metabolism & Nutrition Section Editor of Poultry Science, 1995-99, 2005-11
- Associate Editor of Poultry Science, Metabolism & Nutrition Section, 1985-90; 1994-95; 2001-03; 2013-18
- Nutrition Subject Editor of Journal of Applied Poultry Research, 2013-15
- Merck Animal Health Graduate Poultry Research Fellowship Committee, 2015-17
- Zoetis Fundamental Science Award Committee, 2013-14
- 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.
- Associate Editor, 2015-present
Animal Feed Science and Technology
- Editorial Board, 2013-present
World's Poultry Science Association-USA Branch
- Board of Directors, 2002-06
- Chair, Youth Committee, 2003-04
Fulbright Scholar Program
- Reviewer of 11 Fulbright Scholar Program proposals as member of the Biology: Animal 1 Discipline Review Committee, Council for International Exchange of Scholars, 2016
- Reviewer of 11 Fulbright Scholar Program proposals as member of the Life Science: Biochemical 1 Discipline Review Committee, Council for International Exchange of Scholars, 2015
- Reviewer of 25 Fulbright Scholar Program proposals as member of the Life Science: Biochemical 2 Discipline Review Committee, Council for International Exchange of Scholars, 2014
- Reviewer of 12 Fulbright Senior Scholar Program proposals as member of the Life Sciences C - Biochemistry Specialist Discipline Review Committee, Council for International Exchange of Scholars, 2000
- Reviewer of 13 Fulbright Senior Scholar Program proposals as member of the Life Sciences C - Biochemistry Specialist Discipline Review Committee, Council for International Exchange of Scholars, 1999
- Interviewed Austrian applicants for 1993-94 Fulbright Grants, on behalf of the Austrian-American Fulbright Commission, Vienna, Austria. This occurred during my sabbatical year at the University of Vienna as a Fulbright Research Scholar, 1992-93.
Besides several hundred manuscripts reviewed/processed in section/subject editorial roles for Poultry Science and the Journal of Applied Poultry Research, I have served as an ad hoc reviewer of 173 manuscripts for the following 47 other journals (number of manuscripts in parentheses):
African Journal of Agricultural Research (1); African Journal of Biotechnology (1); Analytical Biochemistry (1); Animal: An International Journal of Animal Bioscience (1); Animal Feed Science and Technology (36); Animal Reproduction (1); Archivos de Medicina Veterinaria (1); The Auk: Ornithological Advances (1); Avian Biology Research (1); Biochemistry et Biophysica Acta (1); Biochemie (4); Biological and Trace Element Research (1); British Journal of Nutrition (1); British Poultry Science (18); Comparative Biochemistry and Physiology (8); Domestic Animal Endocrinology (1); Growth, Development, and Aging (1); Journal of Agricultural and Food Chemistry (23); Journal of Agricultural Food Science (1); Journal of Animal Science (1); Journal of Applied Phycology (2); Journal of Applied Poultry Research (8 prior to duty as Nutrition Subject Editor); Journal of the Association of Official Analytical Chemists International (13), Journal of Experimental Biology (3); Journal of Food Science (3); Journal of Lipids (1); Journal of Nutrition (2); Journal of Nutritional Biochemistry (2); Journal of Veterinary Science and Animal Husbandry (1); Lipids (5); Lipids in Health and Disease (1); Livestock Science (8); Mini-Reviews in Medicinal Chemistry (1); Molecular Biology Reports (1); Molecular and Cellular Endocrinology (1); Neuroscience and Biobehavioral Reviews (1); Physiology and Behavior (2); PLoS One (2); Proceedings of the Society for Experimental Biology and Medicine (1); Prostaglandins, Leukotrienes and Essential Fatty Acids (2); Reproduction (1); Scientific Reports (1); South African Journal of Animal Science (1); Springer Plus (1); The Veterinary Journal (1); Theriogenology (2); and Turkish Journal of Veterinary and Animal Sciences (2).
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-present.
Federation of Animal Science Societies (FASS)-American Feed Industry Association New Frontiers in Animal Nutrition Award Committee, 2005.
Appointed by the Acting Vice-Provost & Dean of Graduate Studies, University of Manitoba (Winnipeg, Manitoba, Canada) to serve as the External Examiner at Mohamed Neijat's public defense of her Ph.D. on December 14, 2016.
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.
Nutrition Committee member for the Food Animal Research Symposium, Lexington, KY, November 2-4, 1986.