Influence of Reduced Nitrogen Diets on Ammonia Emissions from Cattle Feedlot Pens

Atmosphere

Karen Galles²  Jay Ham⁵  Elin Westover³  Joshua Stratton¹  John Wagner⁴  Terry Engle³ 

[1] Department of Chemistry, Colorado State University, Fort Collins, CO 80523, USA; E-Mail:;Graduate Degree Program in Ecology and Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO 80523, USA; E-Mail:;Department of Animal Sciences, Colorado State University, Fort Collins, CO 80523, USA; E-Mails:;Department of Animal Sciences, Colorado State University, Southeastern Colorado Research Center, Lamar, CO 81052, USA; E-Mail:;Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO 80523, USA

关键词: livestock;    nitrogen deposition;    ammonia fluxes;    beef feedlots;   

DOI  :  10.3390/atmos2040655

来源: mdpi

【 摘 要 】

Reducing crude protein (CP) in livestock diets may lower ammonia emissions. A feeding trial was conducted with crossbred steers at the Southeast Colorado Research Center in Lamar, Colorado from December 2009 to March 2010. Three diet treatments were investigated: Reduced (11.6% CP), Oscillating (13.5% crude protein 4 days/week and 11.6% CP 3 days/week) and Control (13.5% CP). Intact soil core samples (n = 36 per sampling date) were collected from the pen surfaces on three dates corresponding to 45, 92, and 148 days into the feeding cycle. Four pens from each diet treatment were sampled. Cores were placed into flow-through laboratory chambers for seven days and ammonia fluxes were trapped in acid bubblers that were refreshed every 24 h. Average daily ammonia emissions for the Control diet ranged from 6.6 to 9.4 g NH₃ m⁻²·day⁻¹; average daily emission for the Oscillating diet ranged from 6.3 to 8.8 g NH₃ m⁻²·day⁻¹; and average daily flux for the Reduced diet ranged from 4.1 to 5.8 g NH₃ m⁻²·day⁻¹. Ammonia fluxes from the reduced N treatment were significantly lower (21% to 40%) than from the control diet on the first two sample dates. There was no significant difference between the Oscillating and Control treatments. Reducing CP in cattle feedlot diets may be an effective method for reducing ammonia emissions from pen surfaces. More research is needed to validate these results at commercial scales in different environments to determine if reductions in ammonia can be sustained with lower CP diets without affecting rate of gain, feed efficiency and health.

【 授权许可】

CC BY   
© 2011 by the authors; licensee MDPI, Basel, Switzerland.