169 The impact of corn-based fiber on intestinal morphology and disaccharidase activity in growing pigs

Abstract Dietary changes can modify gastrointestinal architecture and function; thus, our experimental objective was to evaluate how different insoluble corn-based fiber sources (CBF) impact intestinal morphology and brush-border disaccharidases. Two replicates of 28 gilts [26.7 ± 2.5 kg body weight (BW); PIC800 x Camborough; n = 56], were randomly assigned to one of 7 semi-synthetic diets, including a control (CTL) diet with a formulated total dietary fiber (TDF) value of < 1% and 6 diets with a CBF replacing 30% of the corn starch in CTL: dehulled degermed corn (DHDG; TDF = 1.09%), ground corn (COR; TDF = 3.24%), high protein dried distillers grains (HP; TDF = 8.79%), dried distiller’s grains (DDGS; TDF = 9.35%), corn gluten meal (CGM; TDF = 9.88%), and corn bran (BRN; TDF = 13.15%). Pigs were individually housed, and limit-fed 2.4 times maintenance. On d 31, pigs were necropsied, and duodenum, jejunum, ileum, cecum, and colon tissue were collected for histological analysis. Data were analyzed as a linear mixed model with treatment as a fixed effect, replicate as a random slope or fixed effect, where appropriate, using the mixed procedure of SAS. In the duodenum, DHDG, COR, and CGM had the least (P = 0.04) levels of maltase production. Duodenal sucrase production was least in BRN and HP, and DHDG had the greatest (P = 0.04). Duodenal villi height was shortest (P < 0.01) in CTL and BRN compared with HP, DDGS, and CGM, which had the tallest (P < 0.01; Table). Similarly, CTL and BRN had the shallowest duodenal crypt depth (P < 0.01) and tended (P = 0.08) to have a lesser duodenal villus:crypt ratio compared with the other treatments. There were no differences (P > 0.10) among treatments for ileal sucrase or lactase production, but maltase production was greatest in CTL, DDGS, and CGM (P = 0.03). Relative to CTL and BRN, gilts fed HP, DDGS, and CGM, had the tallest (P = 0.01) villus height in the ileum. However, neither ileal villi:crypt ratio nor crypt depth differed (P > 0.10). Cecal crypt depth for BRN increased 32% compared with CTL (P < 0.01). Cecal crypt width was narrowest (P < 0.01) in CTL and DHDG and widest in HP, DDGS, CGM, and CB (P < 0.01). Colon crypt width was narrowest (P < 0.01) in CTL and DHDG and widest in DDGS, CGM, and CB (P < 0.01). Collectively, these data demonstrate that different fiber types have a significant impact on intestinal morphology and disaccharidase production in the growing pig.