Quantification of Methane and Ammonia Emissions in a Naturally Ventilated Barn by Using Defined Criteria to Calculate Emission Rates

Abstract

Simple SummaryDefined criteria for the application of the CO2 balance method in a naturally ventilated barn provided reliable data. This specification enabled the acquisition and quantification of CH4 and NH3 in a naturally ventilated dairy barn, as well as detecting decreasing NH3 emissions affected by supplementing an Acacia mearnsii condensed tannin extract to a dairy cattle ration. Moreover, long-term measurements were possible and can be used to examine feed-related mitigation strategies at a barn level in the future.AbstractExtensive experimentation on individual animals in respiration chambers has already been carried out to evaluate the potential of dietary changes and opportunities to mitigate CH4 emissions from ruminants. Although it is difficult to determine the air exchange rate of open barn spaces, measurements at the herd level should provide similarly reliable and robust results. The primary objective of this study was (1) to define a validity range (data classification criteria (DCC)) for the variables of wind velocity and wind direction during long-term measurements at barn level; and (2) to apply this validity range to a feeding trial in a naturally cross-flow ventilated dairy barn. The application of the DCC permitted quantification of CH4 and NH3 emissions during a feeding trial consisting of four periods. Differences between the control group (no supplement) and the experimental group fed a ration supplemented with condensed Acacia mearnsii tannins (CT) became apparent. Notably, CT concentrations of 1% and 3% of ration dry matter did not reduce CH4 emissions. In contrast, NH3 emissions decreased 34.5% when 3% CT was supplemented. The data confirm that quantification of trace gases in a naturally ventilated barn at the herd level is possible.

Methane Emissions and Milk Fatty Acid Profiles in Dairy Cows Fed Linseed, Measured at the Group Level in a Naturally Ventilated Housing and Individually in Respiration Chambers

“…In addition, certain differences in linseed intake between different group members cannot be ruled out, although this should have been minimized by fixing the cows for a certain period after the linseed supplement was provided. Simultaneous measurements performed by Schmithausen et al [16] in a naturally ventilated experimental housing in two separate sections, similar to the setting of the present experiment, also revealed slight numerical reductions in the CH 4 emissions in lactating cows fed a CH 4 -mitigating supplement (30 g of condensed tannins•kg −1 diet DM; effect reviewed in Beauchemin et al [4]). This report illustrated that it may be possible to detect the CH 4 reduction potential of a feed supplement in a group-level assessment.…”

“…A system-dependent difference was that CH 4 emissions in the experimental dairy housing at the group level included housing-based sources, such as the floor's soiling. Integrated animal and housing emissions are highly relevant from an environmental point of view [16]; however, they may mask differences between feeding treatments. In particular, Hassanat et al [43] recently showed that CH 4 emissions from the manure of linseed-fed cows were higher than those from the manure of cows fed a control diet devoid of linseed.…”

“…However, studies at the group level in relation to dietary interventions are rare, and none of the reports studied the effect of linseed supplementation on total CH 4 emission at the group level. Schmithausen et al [16] quantified CH 4 emissions from cows that were fed diets with different levels of condensed tannins in a naturally ventilated experimental dairy housing using the carbon dioxide (CO 2 ) balance method. Several studies compared CH 4 emissions obtained on individual animals in respiration chambers with those determined at the practical scale using either SF 6 permeation tubes (e.g., [17]), the GreenFeed system (e.g., [18]) or other ventilated hoods (e.g., [13]).…”

Concentrations and Emissions of Ammonia from Different Laying Hen Production Systems of Conventional Cage, Aviary and Natural Mating Colony Cage in North China Plain

“…Livestock production is one of the major sources of NH 3 to the atmosphere, which is estimated to contribute 34-40% of global NH 3 emissions [1]. NH 3 can irritate the eyes and respiratory membranes, and develop chronic stress, which is a threat to workers and animals and has been classified as a hazardous substance under EPCRA [2].…”

“…Average NH 3 emission rates on the first and second day of manure accumulation in CC, AV, and NM (mg/h•hen)1 . The data after manure removal was analyzed on the first day 2.…”