Microbial succession in the gastrointestinal tract (GIT) of the preweaned pig

To more closely establish microbial succession patterns throughout the GIT of the neonatal pig, 16S rRNA gene sequence libraries were constructed using genomic DNA extracted from digesta. Forty-eight sow-reared piglets from 6 litters were killed at each (n = 6) of 0.25, 0.5, 1, 2, 3, 5, 10 and 20 days of age to permit collection of digesta from stomach, small intestine and distal intestine (cecum and colon). Extracted genomic DNA was pooled within intestinal location by days of age and amplified using universal 16S rRNA gene PCR primers. The resultant PCR products were cloned and sequenced (21-27 per pool, 604 total sequences) to identify bacteria. Bacterial succession profile was similar in all 3 gut locations. Clostridiaceae family were the major species identified until 0.5 days of age but were rapidly displaced by Streptococcaceae on day 1. Starting on day 5. Lactobacillaceae were identified to be predominant while percentages for all other species declined and remained below 2% of total identified species. Enterobacteriaceae were identified in significant numbers at days 0.25 and 0.5 only. This data extends knowledge of succession patterns to proximal GIT locations and identifies a short early postnatal period with abundant Streptococcaceae. (C) 2010 Elsevier B.V. All rights reserved.