|Hales Paxton, Kristin|
Submitted to: Waste to Worth Conference
Publication Type: Proceedings
Publication Acceptance Date: 2/2/2015
Publication Date: 3/1/2015
Citation: Spiehs, M.J., Hales, K.E. 2015. Use of zilpaterol hydrochloride to reduce odors and gas production from the feedlot surface when beef cattle are fed diets with or without ethanol byproducts. In: Proceedings Waste to Worth:Spreading Science and Solutions, March 31-April 3, 2015, Seattle, WA. Available: http://articles.extension.org/pages/72870.
Interpretive Summary: Cattle feedlot diets that are high in crude protein (nitrogen) can increase odors that are emitted from cattle feedlots. Wet distillers grains with solubles (WDGS) are a common feedstuff used in cattle finishing diets. Inclusion of distillers grains in feedlot diets, increases the crude protein content of the diet. Zilpaterol hydrochloride is a supplement fed to cattle for a short period of time (21 days) near the end of the finishing phase to improve efficiency of lean gain. Improvements in feed efficiency and growth potentially decrease nitrogen excretion from cattle. Therefore, the use of this supplement in feedlot diets, especially those with high crude protein, may reduce the concentration of odorous compounds on the feedlot surface. A study was conducted to determine if the inclusion of zilpaterol hydrochloride in feedlot diets containing 0 or 30% distillers grains would affect odorous compounds on the feedlot surface. The results indicated that inclusion of zilpaterol hydrochloride was effective in lowering the concentration of several odorous sulfide compounds in fresh feces of cattle fed diets containing 30% WDGS. Ammonia emissions were not affected by the inclusion of zilpaterol hydrochloride in the finishing diet.
Technical Abstract: Many malodorous compounds emitted from the feedlot surface of beef finishing facilities result from protein degradation of feces and urine. The inclusion of wet distillers grain with solubles (WDGS) in beef finishing diets has been shown to increase nitrogen excretion which can increase odorous compounds in waste. Zilpaterol hydrochloride (ZH) is a supplement fed to cattle for a short period of time (21 days) near the end of the finishing phase to improve efficiency of lean gain. Improvements in feed efficiency and lean tissue accretion potentially decrease nitrogen excretion from cattle. Therefore, the use of ZH in feedlot diets, especially those containing WDGS, may reduce the concentration of odorous compounds on the feedlot surface. The objective of this study was to determine if the addition of ZH to beef finishing diets containing 0 or 30% WDGS would decrease odor and gas production from the feedlot surface. Sixteen pens of cattle (25-28 cattle/pen) were used in a 2 x 2 factorial study. Factors included 0 or 30% WDGS inclusion and 0 or 84 mg/steer daily ZH for 21 d at the end of the finishing period. Each of the four following treatment combinations were fed to 4 pens of cattle: 1) finishing diet containing 0% WDGS and 0 mg ZH, 2) finishing diet containing 30% WDGS and 0 mg ZH, 3) finishing diet containing 0% WDGS and 84 mg/animal daily ZH and 4) finishing diet containing 30% WDGS and 84 mg/animal daily ZH. A minimum of 20 fresh fecal pads were collected from each feedlot pen on six occasions. Samples were mixed within pen and a sub-sample was placed in a small wind-tunnel. Duplicate samples for each pen were analyzed. Odorous volatile organic compounds were collected on sorbent tubes and analyzed for straight-chain fatty acids, branched-chain fatty acids, aromatic compounds, and sulfide compounds using a thermal desorption-gas chromatograph-mass spectrometry. Ammonia (NH3) production was measured using a Model 17i Ammonia Analyzer, and hydrogen sulfide (H2S) was measured using a Model 450i Hydrogen Sulfide. Inclusion of ZH in beef finishing diets was effective in lowering the concentration of total sulfides, total branched-chain fatty acids, and hydrogen sulfide from fresh cattle feces. Inclusion of 30% WDGS to beef feedlot diets increased the concentration of odorous aromatic compounds from feces. Ammonia concentration was not affected by the inclusion of either WDGS or ZH in the finishing diet. Producers may see a reduction in odorous emissions when ZH are fed to beef finishing cattle.