Investigation of aerobic and anaerobic microflora and volatile fatty acids in the jejunum, ileum, and cecum of the weanling pig

Experiment 1. The purpose of this experiment was to characterize aerobic and anaerobic microflora, volatile fatty acids (VFA) , pH, dry matter, and lactate (L+ and D-) concentrations in the jejunum, ileum, and cecum of pigs weaned at 17 or 24 d of age. Pigs were surgically fitted with T-cannulas in either the jejunum, ileum, or cecum at approximately 14 d of age. After a 3 d recovery period, pigs were randomly assigned a weaning age and intestinal and fecal contents were sampled at 17, 20, 24, 27, 31, and 34 d of age. Noncannulated littermates were also sacrificed at weaning with intestinal, fecal, and blood samples taken to determine effects of carmulation. No differences (P > .05) were noted in serum cortisol or microbial populations between cannulated and noncannulated pigs. Dry matter percentage and pH levels were higher (P < .05) in the cecum than in the ileum or jejunum. Unweaned pigs maintained higher (P < .05) lactobacilli populations than weaned pigs; however, populations declined (P < .05) in both groups postweaning. Fecal populations of E. coli and lactobacilli declined (P < .05) postweaning; whereas, fecal bifidobacteria populations increased (P < .05) regardless of weaning age. VFA levels were higher (P < .05) in the cecum versus the jejunum or ileum and lactate (L+) tended (P < .07) to be higher in the jejunum and ileum versus the cecum. Weaning and weaning age were determined to have significant effects on microflora and VFA concentrations.

Experiment 2. The purpose of this experiment was to investigate the effect of dietary galactose on aerobic and anaerobic microflora, volatile fatty acids (VFA), pH, dry matter, and lactate (L+ and D-) concentrations in the ileum and cecum of weanling pigs. Pigs were surgically fitted with T-carmulas in either the ileum or cecum at approximately 14 d of age. After a 4 d recovery period, pigs were weaned at 18 d of age and randomly assigned either a control or treatment diet.The control diet was a phase starter diet based on corn starch and the treatment diet was similar except for galactose replacing a portion (13%) of the corn starch. The diets were mixed with water and offered twice daily. Intestinal and fecal samples were obtained at 18,21, 25,28, 32, and 35 d of age. Digesta pH increased (P < .05) following weaning regardless of collection site. Dry matter percentage was higher (P < .01) in cecal contents compared to ileal contents. Galactose did not affect populations of microflora or VFA concentrations, except for a tendency (P < .08) to prolong E. coli populations postweaning and to decrease acetate production. Lactate (L+) concentrations were greater (P < .05) in ileal versus cecal contents. Results indicate that galactose fed at this level incurs only minimal changes in microflora and VFA concentrations in the ileum and cecum of weanling pigs.