When Holstein cattle were included in the life cycle
analysis, the mean carbon emission for the region
decreased to 18.3 ± 1.7 kg CO2e/kg CW (Table 6).
This occurred because of the relatively low emissions
and resource use allocated to a Holstein calf
obtained from a dairy operation (Stackhouse-Lawson
et al., 2012). Maintenance of the breeding stock in a
beef cattle production system contributes a major portion
of the environmental footprint of beef production.
Because the dairy calf is a byproduct of the dairy farm,
it has a much smaller footprint. The dairy cow also has
a lower footprint than a beef cow because a portion of
her environmental footprint has been allocated to milk
production (Rotz et al., 2010). Because Holstein cattle
make up a relatively small portion of the total cattle
in this region, these differences had a relatively small
impact on the regional footprint.