The carbon footprint of beef and beef × dairy crossbred steers under different growing regimens.

Beef × dairy crossbred steers are becoming an increasingly important source of feeder cattle within the U.S. beef supply chain. However, there has been minimal investigation into greenhouse gas emissions [GHG; kg carbon dioxide equivalence (CO2e)] or carbon footprint [kg CO2e/kg hot carcass weight (HCW); C footprint] from beef × dairy crossbred steers in the U.S. Furthermore, how beef × dairy crossbred steers compare with beef steers subjected to different growing systems (calf-fed vs. stocker) is not well explored. The objective of this analysis was to compare the C footprint of beef × dairy and beef steers, with or without a stocker phase, from growing through finish. International Panel on Climate Change tier 2 methodology was employed using previously published performance data. Beef and beef × dairy crossbred steers were either grown in a season-long stocker system where they grazed mixed-grass prairie prior to finishing (yearling-fed) or were grown in the feedlot (calf-fed). Cattle grown in a stocker system had 4.6% and 11.3% greater C footprint than calf-fed steers for beef × dairy and beef steers, respectively. This increase was due to greater emissions arising during grazing compared with confined feeding systems. Furthermore, beef × dairy crossbred steers had 11.7% greater C footprint when calf-fed and 3.8% greater C footprint when yearling-fed compared with beef steers. These results suggest that direct emissions arising from growing cattle through finish are greater from beef × dairy sourced steers than beef. However, considering the known importance of dam emissions to overall C footprint, we conducted a secondary analysis to examine how this impacts the final emission estimate. When dam emissions are allocated to these C footprints, beef × dairy crossbred steers will have a considerably lower predicted C footprint compared with beef steers, as only a fraction of dairy dam's GHG emissions will be allocated to beef production. Future research is needed which expands system boundaries to more aptly compare the C footprint of beef produced from beef and beef × dairy crossbred steers.