| Editorial Board | Small Ruminant Research Journal; | 1990–Present |
| Editorial Board | Open Journal of Animal Science; | 2010-Present |
| Editorial Board | Foods and Nutrition Sciences; | 2011-Present |
| Chair, Vice Chair, Secretary | American Dairy Science Association, Dairy Foods Division; | 2009, 2010, 2011, 2012 |
| Symposium Speaker | First Asia Dairy Goat Conference, Kuala Lumpur, Malaysia, | April 9-12, 2012 |
| Adjunct Professor | Mongolia International University, Ulaanbaatar, Mongolia, | May, 2012- Present |
| Reviewer | Reviewer for the Middle East-Israel Cooperative Proposal of US AID projects | 2009 |
| Session Chair | 9th International Conf. on Goats, Queretaro, Mexico | 2008 |
| Invited Lecturer | Mercolactea National Conference, Cordova, Argentina, and National Institute of Industrial Technology Symposium in Buenos Aires, Argentina | May 8-14, 2008 |
| Symposium Speaker | 2nd International Symposium on Quality of Goat Products. Bella, Italy | May 22-27, 2007 |
| Symposium Speaker | The 2nd International Goat Symposium, Celaya, Mexico. | October 8-12, 2005 |
| Grants Reviewer | Reviewer for the USDA NRI Research Grants Proposals. | 2005-Present |
| Symposium Speaker | International Dairy Federation (IDF) Symposium on Future of Dairy Sheep and Goat Sectors. Zaragoza, Spain, | October, 2004 |
| Symposium Speaker and Roundtable Discussant | The 8th International Conference on Goats, Pretoria, South Africa | 2004 |
| Session Chair | Milk and Dairy Processing Session, IX World Conference on Animal Production, Porto Alegre, Brazil | 2003 |
| Adjunct Faculty | Adjunct professor of the University of Georgia, Athens, GA | 2001 to Present |
| Session Co-chair | Small Ruminant Dairy Research-Milk Quality and Dairy Foods, Joint Annual Meeting of American Dairy Science Assoc. and American Society of Animal Science, Baltimore, MD | 2000 |
| Grants Reviewer | Reviewer for the USDA Small Business Innovation Grants proposals | 1997, 2002 and 2005 |
| Adjunct Professor | Northern Baptist Theological Seminary, Chicago, IL | 1995-1997 |
| Committee | International Dairy Federation (IDF), Member in US committee for Somatic Cell Counts and Milk Quality | 1991-2000 |
| US Chair person | The US Chair Person, Committee on Heavy Metal in Milk, International Dairy Federation | 1991 to 2000 |
| Session Chair | Milk Production and Diseases Session, The 2nd International Colloquium on Goat Disease and Production, Niort, France, | 1989 |
| Session Chair | Milk and Milk Products Session, VI World Conference on Animal Production, Helsinki, Finland | 1988 |