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ARS Home » Midwest Area » Madison, Wisconsin » U.S. Dairy Forage Research Center » Dairy Forage Research » Research » Publications at this Location » Publication #318273
Title: Transformation of nitrogen contained in alfalfa silage, corn silage, corn grain and soybean meal into milk, manure and recycled back to corn

Author
item Powell, Joseph
item BARROS, TIAGO - University Of Wisconsin
item DANES, MARINA - University Of Wisconsin
item WATTIAUX, MICHEL - University Of Wisconsin

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/15/2015
Publication Date: 11/15/2015
Citation: Powell, J.M., Barros, T., Danes, M., Wattiaux, M. 2015. Transformation of nitrogen contained in alfalfa silage, corn silage, corn grain and soybean meal into milk, manure and recycled back to corn [abstract]. ASA-CSSA-SSSA Annual Meeting Abstracts. [CD ROM]. Version 1.1. Madison, WI: ACS Societies.

Interpretive Summary:

Technical Abstract: To better understand the transformative nature of feed nitrogen (N) on confinement dairy farms (cows fed stored feed in barns), a series of cow, laboratory, and field experiments was undertaken to quantify the relative amounts of N contained in individual ration components that are secreted in milk, excreted in urine and feces, taken up by crops after manure application to soil, and lost as ammonia (NH3) and nitrous oxide (N2O) from barns and soils. Alfalfa silage (AS), corn silage (CS), corn grain (CG), and soybeans (SB) were enriched in the field with the stable isotope 15N. Each 15N-enriched component was then fed individually to mid-lactation cows as part of a total mixed ration (TMR). Highest fertilizer 15N incorporation (atom % 15N) was achieved with CG (2.040) and CS (1.857), and lowest with SB (1.385) and AS (0.730) due to 15N dilution by the atmospherically-fixed N by these legumes. The percent consumed feed N secreted in milk for AS, CS, CG and solvent-extracted soybean meal (SBM) was approximately 20.2, 19.2, 21.2 and 25.5 (P=0.178), respectively; feed N excreted in urine was 33.7, 26.2, 32.4, and 34.7 (P=0.024), respectively; and feed N excreted in feces was 46.5, 49.6, 47.7 and 40.9 (P=0.127), respectively. The percent of field-applied manure N from AS, CS, CG and SBM taken by corn (harvested as silage) was 33.4, 30.5, 34.7 and 38.1 (P=0.074). Feces and urine from 15N enriched AS, CS, CG and SBM will be applied to laboratory emission chambers that simulate barn floors and field soil surfaces, and 15NH3, 15NH4 15NO3 and 15N2O will be measured.