Submitted to: Joint Meeting of the ADSA, AMSA, ASAS and PSA
Publication Type: Abstract Only
Publication Acceptance Date: 4/30/2010
Publication Date: 7/11/2010
Citation: Earing, J.E., Durig, A.C., Gellin, G.L., Flythe, M.D., Lawrence, L.M. 2010. Profiling the Change in Fecal Microbial Populations of Mares and Foals Over Time. Joint Meeting of the ADSA, AMSA, ASAS and PSA. Interpretive Summary:
Technical Abstract: The gastrointestinal tract of the mature horse contains a complex community of microorganisms, many of which aid in digestion. Little information is available concerning the establishment of these microbial populations in young horses. The limited research that has been conducted has utilized culture-dependant methods, but culture-independent methods have revealed that cultivation underestimates species diversity. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) is a molecular technique that can be used to evaluate diversity in microbial communities. The objective of this study was to compare the microbial profiles of the feces of mares and foals using PCR-DGGE in an attempt to describe bacterial colonization in the equine gut. The hypothesis was that foals would be born sterile, and would be indistinguishable from mares by 12 wk of age. Nine mare/foal pairs were used for the study. Fecal samples were collected from each mare and foal as the foal matured and subjected to PCR-DGGE. Comparisons between mares and foals were made using UPGMA cluster analysis and reported as percent similarity. The mean similarity between mares and their foals was 11% on the day of parturition (d 0; n=2), 51% on d 1 (n=4), 52% on d 4 (n=3), 67% at wk 2 (n=4), 71% at wk 6 (n=5), and 70% at wk 12 (n=5). These results indicate that most of the colonization events occurred within the first few days of the foal’s life, which is consistent with a study utilizing culture-based techniques. By wk 2, the mean similarity between mares and foals was numerically higher than the mean similarity among mares (61%), suggesting that by 2 wk of age the bacterial species found in the foal’s gut are similar to those found in the mature horse. While PCR-DGGE can be used to examine the diversity of bacteria present in the gut, it does not estimate the relative abundance of the bacterial populations. Also, the presence of bacterial DNA in feces suggests, but does not prove, colonization of the gut by the respective bacterial populations.