Laser methane detector-based quantification of methane emissions from indoor-fed Fogera dairy cows
Date
2021-01-01
Journal Title
Journal ISSN
Volume Title
Publisher
AAAP
Abstract
Objective: Portable laser methane detectors (LMDs) may be an economical means of
estimating CH4 emissions from ruminants. We validated an LMD-based approach and
then used that approach to evaluate CH4 emissions from indigenous dairy cows in a dryland
area of Ethiopia.
Methods: First, we validated our LMD-based approach in Simmental crossbred beef cattle
(n = 2) housed in respiration chambers and fed either a high- or low-concentrate diet. From
the results of the validation, we constructed an estimation equation to determine CH4
emissions from LMD CH4 concentrations. Next, we used our validated LMD approach to
examine CH4 emissions in Fogera dairy cows grazed for 8 h/d (GG, n = 4), fed indoors on
natural-grassland hay (CG1, n = 4), or fed indoors on Napier-grass (Pennisetum purpureum)
hay (CG2, n = 4). All the cows were supplemented with concentrate feed.
Results: The exhaled CH4 concentrations measured by LMD were linearly correlated with
the CH4 emissions determined by infrared-absorption-based gas analyzer (r
2
= 0.55). The
estimation equation used to determine CH4 emissions (y, mg/min) from LMD CH4 concentrations (x, ppm m) was y = 0.4259x+38.61. Daily CH4 emissions of Fogera cows estimated
by using the equation did not differ among the three groups; however, a numerically greater
milk yield was obtained from the CG2 cows than from the GG cows, suggesting that Napiergrass hay might be better than natural-grassland hay for indoor feeding. The CG1 cows had
higher CH4 emissions per feed intake than the other groups, without significant increases
in milk yield and body-weight gain, suggesting that natural-grassland hay cannot be recommended for indoor-fed cows.
Conclusion: These findings demonstrate the potential of using LMDs to valuate feeding
regimens rapidly and economically for dairy cows in areas under financial constraint, while
taking CH4 emissions into consideration.
Description
Publication history: Accepted - 14 December 2020; Published online - 1 January 2021.
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Article
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Keywords
Indoor Feeding, Ethiopian Dryland, Fogera Dairy Cow, Laser Methane Detector, Methane Emissions, Napier Grass
Citation
Kobayashi, N., Hou, F., Tsunekawa, A., Yan, T., Tegegne, F., Tassew, A., Mekuriaw, Y., Mekuriaw, S., Hunegnaw, B., Mekonnen, W. and Ichinohe, T. (2021) ‘Laser methane detector-based quantification of methane emissions from indoor-fed Fogera dairy cows’, Animal Bioscience, 34(8), pp. 1415–1424. doi: 10.5713/ab.20.0739.