Mid-Flock and Post-Harvest Spatial Characterization of Broiler Litter Gas Flux and Nutrients

Abstract

The purpose of this work was to quantify the spatial variability of litter surface gas flux of NH(3), N(2)O and CO(2) while making concurrent measurements of litter temperature and assessing litter moisture content, pH, total N and total C from laboratory analyses. Two U.S. commercial broiler houses were intensively sampled along a grid for litter properties and gas flux on a farm in Mississippi (humid subtropical climate) where the original bedding material was pine wood shavings. Before chicks were placed, the average gas flux from both houses was: 156 mg NH(3)/m(2)/h, 4.4 mg N(2)O/m(2)/h and 6440 mg CO(2)/m(2)/h. At mid-flock and after birds were harvested, pooled values from 44 locations resulted in: 260 mg NH(3)/m(2)/h, 13.1 mg N(2)O/m(2)/h and 13100 mg CO(2)/m(2)/h and 351 mg NH(3)/m(2)/h, 15.1 mg N(2)O/m(2)/h and 18400 mg CO(2)/m(2)/h, respectively. A greater degree of data variability resulted from measurements over time rather than between the houses. A good example is greater litter moisture near sidewalls during the post harvest measurement. All parameters were depicted as color contour plots; upper extremes for gas flux occurred between feeders and waterers. Tabular values cannot convey the complexity of litter surface characteristics and relationships. The efficacy of the data will be best derived by the user’s goal for improving bird productivity and management.