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Young male pigs consumed a diet of fatty minced beef, safflower oil, skim milk powder, sucrose, cornstarch and wheat bran. Starch provided 50% of total daily energy either as low amylose cornstarch, high amylose (amylomaize) cornstarch or as a 50/50 mixture of corn and high amylose starch. Neither feed intake nor body weight gain as affected by dietary starch. Final plasma cholesterol concentrations were significantly higher than initial values in pigs fed the 50/50 mixture of corn and high amylose starch. Biliary concentrations of lithocholate and deoxycholate were lower in pigs fed high amylose starch. Large bowel length correlated positively with the dietary content of high amylose starch. Concentrations of butyrate in portal venous plasma were significantly lower in pigs fed high amylose starch than in those fed cornstarch. Neither large bowel digesta mass nor the concentrations of total or individual volatile fatty acids were affected by diet. However, the pool of propionate in the proximal colon and the concentration of propionate in feces were higher in pigs fed amylose starch. Concentrations of starch were uniformly low along the large bowel and were unaffected by starch type. In pigs with cecal cannula, digesta starch concentrations were higher with high amylose starch than with cornstarch. Electron micrographic examination of high amylose starch granules from these animals showed etching patterns similar to those of granules obtained from human ileostomy effluent. It appears that high amylose starch contributes to large bowel bacterial fermentation in the pig but that its utilization may be relatively rapid. KEY WORDS: * pigs * volatile fatty acids * large bowel * starch * steroid metabolism

The effect of a commercial glycanase product (Avizyme TX) on the performance of 4-wk-old broiler chickens fed wheats with low and normal apparent metabolizable energy values was studied. Controls were fed a corn-based diet. Supplementation with the enzyme product significantly (P < 0.01) increased the apparent metabolizable energy of the low metabolizable energy wheat from 12.02 to 14.94 MJ/kg dry matter. The apparent metabolizable energy value of the normal wheat was increased from 14.52 to 14.83 MJ/kg dry matter; this was, however, not significant. Birds fed the low metabolizable energy wheat diet had significantly (P < 0.01) higher digesta viscosity and lower small intestinal starch and protein digestibilities than birds fed the normal wheat diet. Chickens fed the low metabolizable energy wheat tended to grow less than those fed the normal wheat diet. When the low metabolizable energy wheat + enzyme diet was fed, digesta viscosity was significantly (P < 0.01) lower (20.28 vs. 10.36 mPa[centered dot]s), and small intestinal digestibility coefficient of starch was significantly (P < 0.01) greater (0.584 vs. 0.861) relative to values in birds fed the low metabolizable energy wheat diet alone. Although the protein digestibility coefficient also increased from 0.689 to 0.745, the difference was not significant. Weight gain and feed efficiency of birds fed the low metabolizable energy wheat + enzyme equaled those of controls. The enzyme product significantly (P < 0.01) increased the solubilization of non-starch polysaccharides within the gastrointestinal tract of birds fed both types of wheat diets. This experiment demonstrated that non-starch polysaccharide-degrading enzymes markedly increase the nutritive value of low metabolizable energy wheat broiler chicken diets, suggesting that increased level of viscous non-starch polysaccharides may cause the low apparent metabolizable energy contents of some wheats. INDEXING KEY WORDS: apparent metabolizable energy; wheat; non-starch; polysaccharides; enzyme supplementation; chickens

Male pigs were fed a low fiber beef diet (control) or that diet with additional fiber either as wheat bran, oat bran or baked beans. Total large bowel digesta and volatile fatty acid (VFA) pools were highest in pigs fed the diet with baked beans, intermediate in those fed the diets with oat bran and wheat bran and lowest in those fed the control diet. In all groups digesta mass and total VFA pools rose from the cecum and then fell to the distal colon, and incremental effects of diet were the same at all sampling sites. For acetate and propionate pools there was a significant interaction between diet and anatomical site, but data conversion to logarithms abolished this interaction, indicating that all dietary effects were proportionately the same across sections. Consumption of the diets with wheat bran, oat bran and baked beans increased the total large bowel butyrate pool compared with consumption of the control diet. Digesta H+ concentrations fell along the large bowel and correlated positively with VFA concentrations in the median colon. Portal venous VFA concentrations correlated with VFA in the proximal colon only. Plasma cholesterol and biliary steroids were unrelated to portal venous propionate concentrations. J. Nutr. 123: 133-143, 1993.

The role of the ceca in the anti-nutritive effect of wheat pentosans was studied in intact and cecectomized broiler chickens. Addition of wheat pentosans (equivalent to 30 g pure arabinoxylans/kg diet) depressed the digestibilities of starch, protein and fatty acids in both types of birds. Cecectomized birds were less efficient (P < 0.01) in dry matter and energy utilization, but starch digestion was not influenced by cecectomy. Inclusion of isolated wheat pentosans decreased the fecal protein digestibility by 18% in intact birds and by 7% in cecectomized chickens, with the bird type x pentosan interaction being significant (P < 0.05). The ileal pentosan digestibility was not affected either by addition of isolated pentosans or by cecectomy; however, the fecal pentosan digestibility was significantly (P < 0.001) influenced. Thus, in intact birds the fecal pentosan digestibility coefficient was 0.216 in birds fed the control diet and 0.646 in those fed the diet with wheat pentosans; in cecectomized chickens the corresponding values were 0.193 and 0.399, indicating a significant influence of the hindgut microflora on pentosan digestion. The ileal and fecal digestibilities of fatty acids were also determined. There was no interaction between bird type and pentosan addition in the ileal digestibilities of fatty acids. Depressions in the fecal digestibilities of fatty acids 14:0 and 18:0 were significantly (P < 0.05) greater in intact birds. Our results indicate that the anti-nutritive effects of wheat pentosans in poultry are partially due to an increased activity of hindgut microflora. J. Nutr. 122: 2457-2465, 1992.

Examines the effects of Australian acacia gums and gum arabic to non-strach polysaccharide accumulation in the cecum of rats. Sugar composition of acacia gums; Food consumption and body weight gain; Plasma and liver lipids; Effect of diet on cecal polysaccharide levels; Effect of diet on cecal volatile fatty acids.