Abstract #517

# 517
Morphological, microbiological, and biochemical development of ruminant gastrointestinal tract.
Carl J. Yeoman1, Glenn C. Duff*1, 1Department of Animal and Range Sciences, Montana State University, Bozeman, MT.

It is well recognized that morphological development of the rumen is dependent on diet and microbiota. For example, dietary concentrates stimulate the microbial production of VFA, including butyrate. Butyrate is the primary form of energy to the developing rumen wall and promotes development of ruminal papillae. Microbial colonization of the ruminant gut is complex and begins at birth. Microbes found on the teat and in the colostrum rapidly replace early colonizers from the vagina and a dynamic succession takes place until a mature climax community forms between 180 to 360 d of age. By using direct-fed microbials, including live cultures of Lactobacillus acidophilus, L. bulgaricus, Streptococcus thermophilus, and Aspergillus oryzae in place of colostrum, we found no loss (P > 0.05) in ADG or increase (P > 0.05) in intake in neonatal lambs. In Holstein calves supplementation of L. acidophilus and Propionibacterium freudenreichii resulted in increased (P < 0.05) gastrointestinal villus height, crypt depth, and total height (crypt plus villus) before weaning with average ruminal papillae width greater (P < 0.01) in calves fed the live cultures versus control calves after weaning. Genus populations of Baceroides, Roseburia, and Eubacterium were greater (P < 0.05) in fecal samples collected in nonscouring calves versus scouring calves. Using serum β-hydroxybutyrate as a marker in serum for ruminal development, milk feeding regimen (bottle versus trough) and housing (group versus individual) did not appear (P > 0.10) to affect ruminal development. Alterations of microbiota in the rumen to hasten ruminal development deserves attention to potentially improve animal health and performance.

Key Words: ruminant, gastrointestinal, development

Speaker Bio
Glenn C. Duff is the Department Head for Animal and Range Sciences at Montana State University.  Dr. Duff served as Interim Dean of the College of Agriculture and Director of the Montana Agricultural Experiment Station from September 2013 to December 2014.  Dr. Duff served as Head of the Department of Animal and Range Sciences at Montana State University from 2010 to 2013.  In addition to his administration assignment, Dr. Duff taught a senior level beef production course and a graduate level seminar course.  His research program focuses on effects of stress (particularly cold stress) on health and performance of beef cattle.  Prior to joining Montana State University, Dr. Duff was on faculty in the Department of Animal Sciences at the University of Arizona (UA).   Dr. Duff’s research program at the University of Arizona focused on feedlot nutrition, in particular, raising Holstein bull calves from birth through harvest.  Dr. Duff taught an Applied Nutrition course, an Advanced Nutrition – Feedlot, Companion Animal Nutrition, and an Applied Experimental Design graduate courses at the UA.   In addition to research and teaching, Dr. Duff was active in departmental, college, and university service activities.  From 1996 to 2001, Dr. Duff was an Assistant Professor and Superintendent for New Mexico State University’s Clayton Livestock Research Center in Clayton, NM.   Dr. Duff has published 76 peer-reviewed publications, 7 book chapters, numerous proceedings papers and abstracts.  He has attracted approximately $870,000 in external support for his research programs.  Dr. Duff is also active in community service including serving on a local organization in Clayton, NM (Youth Supporters) and was active in Rotary International where he served on the board of director, President Elect, and President of the Rotary Club of Tucson, Sunset.  Glenn and Donna have a son finishing a MBA degree at the University of Arizona.