Greenhouse Gas Emissions from Calf- and Yearling-Fed Beef Production Systems, With and Without the Use of Growth Promotants.
A spring calving herd consisting of about 350 beef cows, 14-16 breeding bulls, 60 replacement heifers and 112 steers were used to compare the whole-farm GHG emissions among calf-fed vs. yearling-fed production systems with and without growth implants. Carbon footprint ranged from 11.63 to 13.22 kg CO₂e per kg live weight (19.87-22.52 kg CO₂e per kg carcass weight). Enteric CH₄ was the largest source of GHG emissions (53-54%), followed by manure N₂O (20-22%), cropping N₂O (11%), energy use CO₂ (9-9.5%), and manure CH₄ (4-6%). Beef cow accounted for 77% and 58% of the GHG emissions in the calf-fed and yearling-fed. Feeders accounted for the second highest GHG emissions (15% calf-fed; 35-36% yearling-fed). Implants reduced the carbon footprint by 4.9-5.1% compared with hormone-free. Calf-fed reduced the carbon footprint by 6.3-7.5% compared with yearling-fed. When expressed as kg CO₂e per kg carcass weight per year the carbon footprint of calf-fed production was 73.9-76.1% lower than yearling-fed production, and calf-fed implanted was 85% lower than hormone-free yearling-fed. Reducing GHG emissions from beef production may be accomplished by improving the feed efficiency of the cow herd, decreasing the days on low quality feeds, and reducing the age at harvest of youthful cattle.
Alberta Agriculture and Rural Development, Lacombe Research Centre, 6000 C & E Trail, Lacombe, AB T4L 1W1, Canada. john.basarab@gov.ab.ca.
John
J
Basarab
Agriculture and Agri-Food Canada, Lacombe Research Centre, 6000 C & E Trail, Lacombe, AB T4L 1W1, Canada. vern.baron@agr.gc.ca.
Vern
V
Baron
Agriculture and Agri-Food Canada, Lacombe Research Centre, 6000 C & E Trail, Lacombe, AB T4L 1W1, Canada. Oscar.LopezCampos@agr.gc.ca.
Óscar
Ó
López-Campos
Agriculture and Agri-Food Canada, Lacombe Research Centre, 6000 C & E Trail, Lacombe, AB T4L 1W1, Canada. Jennifer.Aalhus@agr.gc.ca.
Jennifer
J
Aalhus
The Prasino Group, 12207-42 A Avenue, Edmonton, AB T6J 0X5, Canada. karenhk@prasinogroup.com.
Karen
K
Haugen-Kozyra
Department Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, Canada. Erasmus.Okine@ales.ualberta.ca.
Erasmus
E
Okine
beef; carbon footprint; hormone implant; life cycle assessment; production efficiency