Parker, David B; Meyer, Beverly; Jennings, Tracy; Jennings, Jenny; Dougherty, Holland; Cole, N Andy; PAS, PAS; Casey, Ken

Author(s)

Parker, David B

Meyer, Beverly

Jennings, Tracy

Jennings, Jenny

Dougherty, Holland

Cole, N Andy

PAS, PAS

Casey, Ken

Publication Date

2018

Abstract

Nitrous oxide (N2O) is a greenhouse gas with a higher global warming potential than carbon dioxide (CO2) or methane (CH4). The objectives of this research were to quantify enteric N2O emissions from beef cattle and determine effects of dietary nitrate (NO3) concentrations. Experiments consisted of one in vitro incubation trial and 2 live animal (LA) trials. During the in vitro trial, gas was collected from 4 forage-based and 5 corn-based diets. During the LA trials, emissions were monitored from steers in respiration chambers. In LA trial 1, 5 measurements of 256 to 720 min were conducted on a single steer within a 48-h period. In LA trial 2, measurements were conducted on 4 steers in the absence of manure. Highest in vitro N2O production was from diets containing added NO3 or alfalfa. In vitro N2O increased with dietary NO3 concentrations (r2 = 0.99), with little correlation to dietary CP (r2 = 0.17). Added NO3 decreased CH4 emissions. Mean N2O emission rates (±SD) from the LA trials were 6.93 ± 2.99 mg of N2O∙kg−1 of DMI in trial 1 and 2.20 ± 0.10 mg of N2O∙kg−1 of DMI in trial 2. Mean enteric N2O emissions accounted for 0.35% (LA trial 1) and 0.12% (LA trial 2) of CO2 equivalents. Enteric N2O emission rates were 6 to 40 times lower than values cited in earlier publications. Enteric N2O emission rates were also 58 to 108 times lower than manure emissions. Therefore, efforts to reduce greenhouse gas emissions from beef cattle should focus on enteric CH4 and manure N2O as opposed to enteric N2O.

Citation

The Professional Animal Scientist, 34(6), p. 594-607

ISSN

1080-7446

Link

https://hdl.handle.net/1959.11/29253

Publisher

Elsevier Inc

Title

Enteric nitrous oxide emissions from beef cattle

Type of document

Journal Article

Entity Type

Publication

Author(s)	Parker, David B Meyer, Beverly Jennings, Tracy Jennings, Jenny Dougherty, Holland Cole, N Andy PAS, PAS Casey, Ken
Publication Date	2018
Abstract	Nitrous oxide (N<sub>2</sub>O) is a greenhouse gas with a higher global warming potential than carbon dioxide (CO<sub>2</sub>) or methane (CH<sub>4</sub>). The objectives of this research were to quantify enteric N<sub>2</sub>O emissions from beef cattle and determine effects of dietary nitrate (NO<sub>3</sub>) concentrations. Experiments consisted of one in vitro incubation trial and 2 live animal (LA) trials. During the in vitro trial, gas was collected from 4 forage-based and 5 corn-based diets. During the LA trials, emissions were monitored from steers in respiration chambers. In LA trial 1, 5 measurements of 256 to 720 min were conducted on a single steer within a 48-h period. In LA trial 2, measurements were conducted on 4 steers in the absence of manure. Highest in vitro N<sub>2</sub>O production was from diets containing added NO<sub>3</sub> or alfalfa. In vitro N<sub>2</sub>O increased with dietary NO<sub>3</sub> concentrations (r<sup>2</sup> = 0.99), with little correlation to dietary CP (r<sup>2</sup> = 0.17). Added NO<sub>3</sub> decreased CH<sub>4</sub> emissions. Mean N<sub>2</sub>O emission rates (±SD) from the LA trials were 6.93 ± 2.99 mg of N2O∙kg−1 of DMI in trial 1 and 2.20 ± 0.10 mg of N2O∙kg−1 of DMI in trial 2. Mean enteric N<sub>2</sub>O emissions accounted for 0.35% (LA trial 1) and 0.12% (LA trial 2) of CO<sub>2</sub> equivalents. Enteric N<sub>2</sub>O emission rates were 6 to 40 times lower than values cited in earlier publications. Enteric N<sub>2</sub>O emission rates were also 58 to 108 times lower than manure emissions. Therefore, efforts to reduce greenhouse gas emissions from beef cattle should focus on enteric CH<sub>4</sub> and manure N<sub>2</sub>O as opposed to enteric N<sub>2</sub>O.
Citation	The Professional Animal Scientist, 34(6), p. 594-607
ISSN	1080-7446
Link	https://hdl.handle.net/1959.11/29253
Publisher	Elsevier Inc
Title	Enteric nitrous oxide emissions from beef cattle
Type of document	Journal Article
Entity Type	Publication

Enteric nitrous oxide emissions from beef cattle

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