Abstract
The warming effect of ruminant greenhouse gases is an issue of global concern. This experiment tested the potential for abatement of ruminant gases by offering three levels of concentrate to dairy cows of high and low rumination in a pasture-based automatic milking system. Two uniform groups of cows (n=30/group; milk yield = 352 kg) with consistently high (75th percentile = 6209 min) and low (25th percentile = 47310 min) rumination were randomly assigned to three concentrate treatments offering same temperate pasture (offered at 30 kg DM/cow/d) and grain-based pellet (7 kg DM/cow/d) plus 0, 1.5 or 3 kg DM/cow/d of ground shelled corn. Milk production, rumination, activity, mass flux of CH4 (QCH4) and carbon dioxide (QCO2), and dry matter intake (DMI) determined by use of QCO2 as biomarker, were recorded for 12 d and analyzed with mixed models for a completely randomized design. No effect (P>0.24) of rumination on QCH4 or QCO2 was detected. Offering 1.5 kg of corn increased QCO2, but increasing corn offered to 3 kg reduced QCO2 (P=0.02). A similar numerical trend (P=0.13) to increasing corn feeding was observed for QCH4. Offering 3 kg of corn reduced (P<0.02) total and pasture DMI, and this decrease was associated with a lower (P<0.03) DMI/Activity. Both QCH4/Milk and QCO2/Milk decreased exponentially with increasing milk yield, supporting a dilution of emitted gases as more feed energy is sequestered in milk. The results suggest opportunities to manipulate ruminant gas emissions through allocation of concentrates but warrant further investigation to corroborate this finding.
Original language | English |
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Pages | 46 |
Number of pages | 1 |
Publication status | Published - 16 Nov 2016 |
Event | Australasian Dairy Science Symposium 2016 - The University of Sydney, Sydney, Australia Duration: 16 Nov 2016 → 18 Nov 2016 https://web.archive.org/web/20160308200056/http://adssymposium.com.au/ (Conference website) http://www.publish.csiro.au/AN/issue/8278 (Full papers from Australasian Dairy Science Symposium 2016, published 2017) |
Conference
Conference | Australasian Dairy Science Symposium 2016 |
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Abbreviated title | Science-based Solutions for Australasian Dairy Industries |
Country/Territory | Australia |
City | Sydney |
Period | 16/11/16 → 18/11/16 |
Internet address |
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