P157. Role of the cecum on faecal microbial community structure in finisher pigs using a caecectomized pig model

The cecum is a major site of fermentation of dietary nutrients. In the pig, there is a knowledge gap pertaining to the role of the cecum in nutrient metabolism and health. The objective of this preliminary work was to develop a caecectomized pig model and to evaluate cecum microbial community structure in cecectomized finisher pigs fed a high fibre diet. Caecectomies were performed at the nursery to grower phase transition (∼ 63 d of age) prior to the experiment. A total of 10 barrows (initial BW = 83 kg; ∼112 d of age) were allotted to 1 of 2 treatments (5 replicates/treatment) in a 4 wk experiment. Treatments consisted of caecectomized (CEC-) or cecum intact (CTRL) pigs. All pigs were fed a moderately complex, high fibre (soy hulls included at 25%) finisher diet (3,006 ME kcal/kg) during the entirety of the trial. Data was analysed using PROC MIXED procedures of SAS with treatment as fixed effect and initial BW block as random effect. No differences were observed in BW on d 0 (82.92 vs 83.92 kg) or d 28 (110.78 vs 114.36 kg) between treatments (CEC- vs CTRL, respectively). During wk 4 CTRL pigs tended to have greater (P<0.09) ADFI compared to CEC- pigs (4.39 vs. 3.45 kg/d). Faecal samples (obtained on d 0, 14, and 28) were used to evaluate phylum-level bacterial community structure by sequencing the V4 region of the 16S rRNA gene. No significant differences were observed in microbial community structure between treatments over the time course of the experiment. Preliminary data suggests there may be utility in development of a caecectomized pig model to evaluate the role of the caecum in pig nutrient metabolism and health. Additional analyses are in process to investigate fibre digestion kinetics and bacterial community structure at the genus/species levels.