title: Effects of dietary fiber and reduced crude protein on ammonia emission from laying-hen manure.
abstract: Ammonia (NH(3)) emission is a major concern for the poultry industry. The objective of this research was to determine whether inclusion of dietary fiber and a reduced dietary CP content would decrease NH(3) emission from laying-hen manure. A total of 256 Hy-Line W-36 hens were fed diets with 2 levels of CP (normal and reduced) and 4 fiber treatments in a 2 x 4 factorial arrangement. The fiber treatments included a corn and soybean meal-based control diet and diets formulated with either 10.0% corn dried distillers grains with solubles (DDGS), 7.3% wheat middlings (WM), or 4.8% soybean hulls (SH) to contribute equal amounts of additional neutral detergent fiber. The CP contents of the reduced-CP diets were approximately 1 percentage unit lower than those of the normal-CP diets. All diets were formulated on the basis of digestible amino acid content and were formulated to be isoenergetic. Fresh manure was collected such that pH, uric acid, and Kjeldahl N contents could be measured. The NH(3) emission from manure was measured over 7 d by placing pooled 24-h manure samples in NH(3) emission vessels. Data were analyzed by ANOVA with Dunnett's multiple-comparisons procedure to compare results from the fiber treatments with the control, whereas the main effect of protein was used to compare the normal- and reduced-CP treatments. Dietary corn DDGS, WM, or SH lowered (P <or= 0.01) the 7-d cumulative manure NH(3) emission from 3.9 g/kg of DM manure for the control to 1.9, 2.1, and 2.3 g/kg of DM manure, respectively, and lowered (P < 0.05) the daily NH(3) emission rate. Results of this study showed that dietary inclusion of 10.0% corn DDGS, 7.3% WM, or 4.8% SH lowered NH(3) emission from laying-hen manure; however, reducing the CP content by 1 percentage unit had no measurable effect on NH(3) emission.
authors.affiliation: Department of Animal Science, Iowa State University, Ames, IA 50011, USA.
authors.forename: S A
authors.initials: SA
authors.lastname: Roberts
authors.forename: H
authors.initials: H
authors.lastname: Xin
authors.forename: B J
authors.initials: BJ
authors.lastname: Kerr
authors.forename: J R
authors.initials: JR
authors.lastname: Russell
authors.forename: K
authors.initials: K
authors.lastname: Bregendahl
mesh_terms: D000641:Ammonia / Q000032:analysis*; D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002645:Chickens / Q000378:metabolism*; D004032:Diet / Q000662:veterinary; D004043:Dietary Fiber / Q000494:pharmacology*; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000494:pharmacology*; D004785:Environmental Pollutants; D005243:Feces / Q000737:chemistry*; D005260:Female; D008372:Manure / Q000032:analysis*; D009584:Nitrogen; D010058:Oviposition / Q000502:physiology*
chemical_list: D004043:Dietary Fiber; D004044:Dietary Proteins; D004785:Environmental Pollutants; D008372:Manure; D000641:Ammonia; D009584:Nitrogen