title: Endogenous N-losses in piglets estimated by a [15N]-isotope dilution technique: effect of xylanase addition to a wheat and rye based diet.
abstract: The nitrogen pool of piglets weighing 19.4 +/- 1.4 kg at the beginning of the experiment was labeled with an oral application of ([15N]H4)2SO4 (1.26 [15N]-atom percent excess of dietary N) over a period of 7 d. The labeling period was followed by an equilibration period of 7 d without feeding the labeling compound. The two experimental diets were based on wheat (53%) and rye (25%) and were fed either with or without a xylanase containing enzyme preparation over both experimental periods. Additionally, diets were supplemented with an indigestible marker during the 2nd period of the experiment to allow the calculation of endogenous N-losses in subsequent segments of the digestive tract of the pigs. These endogenous N-losses were estimated at the end of the experiment by analyzing feces, ingesta and urine for [15N]-enrichment assuming that [15N]-enrichment of urine represents the [15N]-enrichment of the precursor pool. Endogenous N-losses were not significantly affected by xylanase addition at any measurement site (stomach, 3 sections of the small intestine, total digestive tract). Endogenous N-proportions of total nitrogen amounted on average for the six pigs to 42 +/- 11% and 56 +/- 5% at the last section of the small intestine and over the whole digestive tract, respectively, which corresponded to endogenous N-losses of 2.8 +/- 1.3 g N/kg DM and 2.0 +/- 0.3 g N/kg DM, respectively.
authors.affiliation: Institut für Tierernährung, Bundesforschungsanstalt für Landwirtschaft (FAL), Bundesallee 50, D-38. 116 Braunschweig, Germany. sven.daenicke@fal.de
authors.forename: S
authors.initials: S
authors.lastname: Dänicke
authors.forename: H
authors.initials: H
authors.lastname: Kluge
authors.forename: G
authors.initials: G
authors.lastname: Dusel
authors.forename: H
authors.initials: H
authors.lastname: Jeroch
mesh_terms: D000821:Animal Feed; D000818:Animals; D000831:Animals, Newborn; D004044:Dietary Proteins / Q000008:administration & dosage / Q000378:metabolism; D005243:Feces / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry / Q000662:veterinary; D005766:Gastrointestinal Contents / Q000737:chemistry; D007201:Indicator Dilution Techniques; D007700:Kinetics; D008297:Male; D009584:Nitrogen / Q000378:metabolism*; D009587:Nitrogen Isotopes; D012434:Secale / Q000378:metabolism; D013552:Swine / Q000378:metabolism*; D014908:Triticum / Q000378:metabolism; D014556:Urine / Q000737:chemistry; D043325:Xylan Endo-1,3-beta-Xylosidase; D014995:Xylosidases / Q000378:metabolism*
chemical_list: D004044:Dietary Proteins; D009587:Nitrogen Isotopes; D014995:Xylosidases; D043325:Xylan Endo-1,3-beta-Xylosidase; D009584:Nitrogen