1. Xylose metabolism in the pig
- Author
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Huntley, Nichole F. and Patience, John F.
- Subjects
0301 basic medicine ,Nitrogen balance ,Swine ,Physiology ,Metabolite ,lcsh:Medicine ,Urine ,Xylose ,Biochemistry ,chemistry.chemical_compound ,Xylose metabolism ,Medicine and Health Sciences ,Metabolites ,Cluster Analysis ,Food science ,lcsh:Science ,Cecum ,Mammals ,Multidisciplinary ,Organic Compounds ,Monosaccharides ,Fatty Acids ,Eukaryota ,04 agricultural and veterinary sciences ,Body Fluids ,Chemistry ,Physical Sciences ,Vertebrates ,Metabolome ,Xylanase ,Hindgut fermentation ,Metabolic Pathways ,Anatomy ,Energy source ,Metabolic Networks and Pathways ,Research Article ,Colon ,Nitrogen ,Carbohydrates ,Excretion ,03 medical and health sciences ,Animals ,Metabolomics ,Dry matter ,Nutrition ,Organic Chemistry ,lcsh:R ,Chemical Compounds ,Organisms ,0402 animal and dairy science ,Biology and Life Sciences ,Water ,040201 dairy & animal science ,Diet ,Gastrointestinal Tract ,Metabolism ,030104 developmental biology ,chemistry ,Amniotes ,lcsh:Q ,Physiological Processes ,Energy Metabolism ,Digestive System - Abstract
It is important to understand if, and to what extent, the pig can utilize xylose as an energy source if xylanase releases free xylose in the small intestine. The experimental objectives were to determine the effects of industry-relevant dietary xylose concentrations and adaptation time on xylose retention efficiency and metabolism, diet digestibility and energy value, nitrogen balance, and hindgut fermentation. Forty-eight pigs were housed in metabolism crates and randomly assigned to one of four treatments with increasing D-xylose levels (n = 12/treatment) in 2 replications of a 22-d experiment with 3 collection periods. The control diet was xylose-free (0%), to which either 2, 4, or 8% D-xylose was added. Adaptation effects were assessed during three fecal and urine collection periods: d 5–7, 12–14, and 19–21. On d 22, pigs from the 0 and 8% treatments were euthanized; cecal and colon digesta were collected. Dietary xylose did not affect the total tract digestibility of dry matter, gross energy, or crude protein (P>0.10). Digesta short chain fatty acids concentrations and molar proportions and cecal pH were not different (P>0.10). This experiment utilized a targeted metabolomics approach to characterize and quantify urine xylose and metabolite excretion. Xylose retention decreased from 60% to 47% to 41% when pigs were fed diets containing 2, 4, or 8% xylose, respectively. In the 4 and 8% treatments, xylose retention was greater in the 2nd and 3rd collection periods compared to the 1st. A comprehensive pathway for xylose metabolism was proposed and D-threitol was confirmed as the major urinary metabolite of xylose. In conclusion, pigs can metabolize xylose, but with considerably lower efficiency than glucose, and may be able to adapt with time to utilize xylose more efficiently.
- Published
- 2018