A diet effect was not observed for CO
2
or CO
2
eq
concentrations or emissions (P > 0.05, Table 9). Similarly, interaction between phase and treatment was not
significant for any variable. However, a phase effect
was observed because CO
2
emissions increased from
537.4 g · d
–1
· pig
–1
during Phase 1 to approximately 2,000 g · d
–1
· pig
–1
during Phases 3 through 5 (
P
<
0.01). The CO
2
emissions based on AU (g · d
–1
· AU
–1
)
showed slightly different pattern compared with emissions based on pig count (g · d
–1
· pig
–1
) in that the highest emission rates were observed during Phase 3.