Effect of galactan on selected microbial populations and pH and volatile fatty acids in the ileum of the weanling pig.

Studies were conducted to determine the effect of galactan on the colonization of E. coli and lactobacilli and ileal pH and volatile fatty acid production in the digestive tract of the weanling pig. In each of two replicate trials, eight 21-d-old nursing pigs were cannulated in the terminal ileum. After a 7-d recovery period, the pigs were weaned and randomly assigned to two test diets: 1) a corn-soybean meal-based control diet and 2) a similar diet containing 1% galactan. On d 1 after weaning, all pigs were orally subjected to K88+ E. coli (2 x 10(9) colony forming units). Ileal digesta samples were collected on d 0, 2, 4, 6, 8, and 10 after weaning and assayed for total E. coli, K88+ E. coli, lactobacilli, pH, and VFA. At the end of the trials, the pigs were killed and digesta samples were collected from the stomach, duodenum, cecum, and colon. Assays similar to those performed on the digesta samples collected from ileal cannulas were performed. Pigs fed 1% galactan had lower (P < .10) ileal pH, lower (P < .05) total E. coli on d 6 and 8, and lower (P < .05) K88+ E. coli concentrations in the ileum than pigs fed the control diet. There were no differences in ADG or gain:feed ratio between diets. The VFA concentrations were not different in the ileum between diets. The VFA were higher (P < .10) on d 0 than on any other day of the study. Acetate and isobutyrate concentrations were lower (P < .10) in the cecum in pigs fed 1% galactan.(ABSTRACT TRUNCATED AT 250 WORDS)