Table 4 Emission factors (EF) for estimation of on-farm GHG emissions from cow-calf and finishing farms.

CH₄

Enteric

CH₄ = [GE × (Y_m/100) × 365)/55.65]

Equation (10.21) in IPCC^a

GE = [(NE_m + NE_a + NE_l + NE_p/REM) + (NE_g/REG]/(DE%/100)

Equation (10.16) in IPCC^a

NE_m: net energy required by the animal for maintenance, MJ day⁻¹

Equation (10.3) in IPCC^a

NE_a: net energy for animal activity, MJ day⁻¹

Equation (10.4) in IPCC^a

NE_g: net energy needed for growth, MJ day⁻¹

Equation (10.6) IPCC^a

NE_l: net energy for lactation, MJ day⁻¹

Equation (10.8) in IPCC^a

NE_p: net energy required for pregnancy, MJ day⁻¹

Equation (10.13) in IPCC^a

REM: the ratio of net energy available in a diet for maintenance to digestible energy

Equation (10.14) in IPCC^a

REG: the ratio of net energy available for growth in a diet to digestible energy consumed

Equation (10.15) in IPCC^a

Y_m: 0.07 (Extensive systems)

(Gavrilova et al., 2019)

Y_m: 0.063 (Semi-intensive and intensive systems)

(Gavrilova et al., 2019)

Y_m: 0.04 (Feedlot)

(Gavrilova et al., 2019)

Manure

CH₄ = VS × B₀ × 0.67 × MCF/100 × MS

Equation (10.23) in IPCC^a

VS = [GE × (1 − DE/100) + (UE × GE)] × [(1 − Ash)/18.45]

Equation (10.24) in IPCC^a

DE: feed digestibility

MCF: values may vary according the manure management system used

Table 10.17 in Gavrilova et al., 2019

Bo: 0.13 (Extensive systems)

Table 10.16 in Gavrilova et al., 2019

Bo: 0.18 (Semi-intensive, intensive, and feedlot systems)

Table 10.16 in Gavrilova et al., 2019

N₂O-N direct

Manure and fertilizer

N₂O-N = (F_SN × EF₁) + (N_ex × EF_3PRP, _CPP)

Equation (11.1) in IPCC^a

EF₁: 0.01 (0.001–0.018)

Table 11.1 in IPCC^a

EF_3PRP, _CPP: 0.004 (0–0.014)

Table 11.1 in Hergoualc’h et al. (2019)

N_ex = N_intake − N_retention

Equation (10.31) in IPCC^a

N_intake: DMI × (CP%/100/6.25)

Equation (10.32) in IPCC^a

N_retention: [(Milk × (Milk PR

Equation (10.33) in IPCCa

%/100)/6.38] + {WG × [268 − (7.03 × Neg/WG)]/(1000 × 6.25)}

Milk PR%: [1.9 + 0.4 × %Fat]

N₂O-N indirect

Manure and fertilizer

N₂O-N = [(F_SN × Frac_GASF) + (F_PRP × Frac_GASM)] × EF₄

Equation (11.9) in IPCCa

Frac Urea: 0.015 (0.03–0.43)

Frac_GASF Ammonium-based: 0.08 (0.02–0.3)

Frac_GASF Nitrate-based: 0.01 (0–0.02)

Frac_GASF Ammonium-nitrate-based: 0.05 (0–0.2)

Table 11.3 in Hergoualc’h et al. (2019)

Frac_GASM: 0.21 (0.00–0.31)

Table 11.3 in Hergoualc’h et al. (2019)

EF₄: 0.01 (0.002–0.018)

Table 11.3 in Hergoualc’h et al. (2019)

CO₂-C direct

Lime application

CO₂-C = (M_Limestone × EF_Limestone) + (M_Dolomite × EF_Dolomite)

Equation (11.12) in IPCC^a

EF_Limestone: 0.12

EF_Dolomite: 0.13

Diesel fuel consumption

CO₂-C = Fuel consumption × EF_Diesel

EF_Diesel: 2.23 kg CO₂eq L⁻¹ diesel⁻¹

UPME (2016)