EFFECTS OF A DIRECT-FED YEAST CULTURE ON ENTERIC MICROBIAL-POPULATIONS, FERMENTATION ACIDS, AND PERFORMANCE OF WEANLING PIGS

In three replicate trials, a total of 36 pigs that had been cannulated at the terminal ileum were used to determine the effects of a Sacchar omyces cerevisiae culture in a phase feeding program (phase I was d 0 to 7 and phase II was d 8 to 21) on performance, ileal microflora, and short-chain fatty acids in weanling pigs. Pigs were cannulated at app roximately 12 d of age, weaned at 17 d of age, and randomly assigned t o one of three treatments: 1) a pelleted phase feeding program, 2) a s imilar program with the inclusion of a live S. cerevisiae culture (1 g /kg), and 3) a nonpelleted feeding program otherwise similar to progra m 2. Ileal samples were collected at 17, 20, 24, 27, 31, 34, and 38 d of age, and samples were analyzed for total E. coli, streptococci, lac tobacilli, yeast, short-chain fatty acids, pH, and dry matter. Perform ance data were also collected. At 41 d of age, pigs were killed and di gesta were collected from various regions of the gastrointestinal trac t. Total intake was less for pigs fed the control diet than for pigs f ed the yeast diets, and overall gains tended to be greater for pigs fe d diets including yeast. Treatment differences were not observed for i leal microflora or short-chain fatty acids in samples obtained from ca nnulas or from the various sites of the gastrointestinal tract. Inclus ion of a live yeast culture in weanling pig diets affected intake and performance but did not alter tested intestinal microflora or net conc entrations of fermentation products.