Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 7/25/2008
Publication Date: 10/16/2008
Citation: Ziemer, C.J., Weber, T.E., Kerr, B.J. 2008. Effect of Corn Germ Meal Inclusion in Pig Diets on Microbial Ecology in the Ileum, Cecum and Colon. In: Proceedings of the 2nd ASM Conference on Beneficial Microbes, Oct. 12-16, 2008, San Diego, CA. p. 53. Interpretive Summary:
Technical Abstract: Inclusion of bio-fuel co-products in swine diets is becoming more common due to greater availability and increasing cereal grain costs. As a result of the ethanol production process, these co-products have lower starch and higher fiber concentrations. In monogastrics, fiber digestion is mainly achieved by the microbes residing in the cecum and colon. Twenty-four pigs were adapted to diets with either corn (control diet) or solvent extracted corn germ meal (CGM). Pigs on the CGM dietary regimen were initially fed diets containing 7.5% CGM which was increased monthly to 15%, 30%, and finally to 40% in the final diet; with the total feeding period lasting 16 weeks. Dietary hemicellulose in the finishing diets was 6.2% in the control and 18.3% in the CGM diets. After 16 weeks, nutrient digestibilities were determined and samples were obtained from the distal ileum, cecum, and proximal colon for bacterial community analysis. Fluorescence in situ hybridization was used to determine the quantity of bacteria (Eub338, Eub338-II, and Eub338-III), archaea (Arc915) and eukarya (Euk1379) in samples, with DAPI used to determine total cell counts. Total tract hemicellulose digestibility was increased in pigs fed CGM (79.1%) when compared to pigs fed the control diet (73.1%) (P = 0.01). No eukaryotes were detected in any of the samples. Inclusion of CGM in diets decreased numbers of bacteria (2.8 × 10-to the 8th cells/ml vs. 5.7 × 10-to the 8th cells/ml, CGM vs. control, P = 0.06) and archaea (1.5 × 10-to the 7th cells/ml vs. 3.5 × 10-to the 7th cells/ml, CGM vs. control, P = 0.01) in the proximal colon but had no effects in the distal ileum and cecum. Concentrations of bacteria and archaea differed (P = 0.02) among intestinal locations as follows: distal ileum (4.4 × 10-to the 7th) < proximal colon (4.3 × 10-to the 8th) < cecum (8.9 × 10-to the 8th bacterial cells/ml) and distal ileum (2.8 × 10-to the 6th) < cecum (1.7 × 10-to the 7th) = proximal colon (2.6 × 10-to the 7th archaeal cells/ml). Archaea accounted for 3.6, 5.4, and 5.0% of total cells in the distal ileum, cecum, and proximal colon, respectively. The microbial community in the gastrointestinal tracts of pigs is predominantly bacteria with archaeal proportions similar to those reported in the rumen, but eukaryotes are absent.