Greenhouse Gas Emissions from Calf- and Yearling-Fed Beef Production Systems, With and Without the Use of Growth Promotants

Animals

John Basarab²  Vern Baron¹  Óscar López-Campos¹  Jennifer Aalhus¹  Karen Haugen-Kozyra³ 

[1] Agriculture and Agri-Food Canada, Lacombe Research Centre, 6000 C & E Trail, Lacombe, AB T4L 1W1, Canada; E-Mails:;Alberta Agriculture and Rural Development, Lacombe Research Centre, 6000 C & E Trail, Lacombe, AB T4L 1W1, Canada;The Prasino Group, 12207-42 A Avenue, Edmonton, AB T6J 0X5, Canada; E-Mail:

关键词: beef;    life cycle assessment;    carbon footprint;    hormone implant;    production efficiency;   

DOI  :  10.3390/ani2020195

来源: mdpi

【 摘 要 】

A spring calving herd (~350 beef cows) over two production cycles was used to compare the whole-farm greenhouse gas (GHG) emissions among calf-fed vs. yearling-fed production systems, with and without growth implants. Farm GHG emissions initially included enteric CH₄, manure CH₄ and N₂O, cropping N₂O, and energy use CO₂. The carbon footprint ranged from 19.9–22.5 kg CO₂e per kg carcass weight. Including soil organic carbon loss from annual cropping and carbon sequestration from perennial pastures and haylands further reduced the carbon footprint by 11–16%. The carbon footprint of beef was reduced by growth promotants (4.9–5.1%) and by calf-fed beef production (6.3–7.5%).

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.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.