title: Effects of dietary fat type and xylanase supplementation to rye-based broiler diets on selected bacterial groups adhering to the intestinal epithelium. on transit time of feed, and on nutrient digestibility.
abstract: Two experiments were conducted to examine the effects of different fat types, i.e., soybean oil (S) and beef tallow (T), in rye-based broiler diets, either unsupplemented (-) or supplemented (+) with xylanase (Avizyme 1300 at 1 g/kg diet), on selected bacterial groups adhering to the epithelium of crop, duodenum, jejunum, and ileum (Experiment 1, 16 d of age), on mean retention time (MRT) of digesta, and on digestibility of N and dry matter in successive segments of the digestive tract (Experiment 2, 24 d of age). Live weight of enzyme-treated and S-fed chickens was significantly higher than that for unsupplemented or T-fed birds, respectively, in both experiments. In Experiment 1, a reduction in bacterial colonization from crop to duodenum was followed by a continuous increase as far as the ileum. Xylanase supplementation significantly reduced enterobacteria and total anaerobe microbes with a similar trend for Gram-positive cocci and enterococci. The latter two groups were significantly enhanced in birds fed T. In Experiment 2, xylanase supplementation resulted in a decrease in MRT in several segments of the digestive tract. This effect was most pronounced in the small intestine, where MRT of 268, 217, 241, and 209 min in groups S-, S+, T-, and T+, respectively, were measured. Apparent digestibility of N and dry matter was slightly improved by xylanase supplementation in the jejunum and ileum. Nitrogen digestibility by the terminal ileum was 80.3, 83.7, 79.4, and 82.2% for the S-, S+, T-, and T+ groups, respectively, and dry matter digestibility amounted to 61.2, 65.5, 62.1, and 64.0%, respectively.
authors.affiliation: Institut für Tierernährung und Vorratshaltung, Landwirtschaftliche Fakultät, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany. sven.daenicke@fal.de
authors.forename: S
authors.initials: S
authors.lastname: Dänicke
authors.forename: W
authors.initials: W
authors.lastname: Vahjen
authors.forename: O
authors.initials: O
authors.lastname: Simon
authors.forename: H
authors.initials: H
authors.lastname: Jeroch
mesh_terms: D000821:Animal Feed; D000818:Animals; D001419:Bacteria; D002645:Chickens / Q000382:microbiology* / Q000502:physiology; D004041:Dietary Fats / Q000378:metabolism*; D004063:Digestion; D005772:Gastrointestinal Transit / Q000502:physiology*; D007413:Intestinal Mucosa / Q000382:microbiology*; D012434:Secale; D043325:Xylan Endo-1,3-beta-Xylosidase; D014995:Xylosidases / Q000494:pharmacology*
chemical_list: D004041:Dietary Fats; D014995:Xylosidases; D043325:Xylan Endo-1,3-beta-Xylosidase