Table 2.
Equations using fermenter DMI as independent variable
| Dependent variables | Equation | AIC | MSE | R2 | P valued |
|---|---|---|---|---|---|
| VFA, %, otherwise stateda | |||||
| Total VFA, mM | Ŷ = 33.5202 + 0.8296 × DMI | 3,253 | 213.0 | 0.73 | 0.01 |
| Acetate | Ŷ = 59.1 | 2,794 | 45.3 | — | >0.05 |
| Propionate | Ŷ = 17.4964 + 0.09516 × DMI | 2,674 | 52.3 | 0.81 | 0.01 |
| Butyrate | Ŷ = 11.41 | 1,851 | 12.0 | — | >0.05 |
| True digestibility, % | |||||
| OM | Ŷ = 86.4729 × (1 – 0.005413)DMI | 2,516 | 29.9 | 0.81 | 0.01 |
| CP | Ŷ = 112.11 – 0.8022 × DMI + 0.001905 × DMI2 | 2,679 | 210.0 | 0.63 | 0.04 |
| NDF digestibility | Ŷ = 90.0419 – 0.4956 × DMI | 2,516 | 111.0 | 0.71 | 0.04 |
| NH3–N, mg/dL | Ŷ = 28.0475 – 0.3098 × DMI + 0.001337 × DMI2 | –115 | 13.0 | 0.08 | 0.02 |
| N flow, g/d | |||||
| NH3–N | Ŷ = 0.3224 | –335 | 0.03 | — | >0.05 |
| NANb | Ŷ = 1.0213 – 0.02418 × DMI + 0.000437 × DMI2 | 16.5 | 0.06 | 0.88 | 0.01 |
| Bacterial-N | Ŷ = 0.3224 – 0.00857 × DMI + 0.000228 × DMI2 | –1.03 | 0.05 | 0.84 | 0.01 |
| Dietary-N | Ŷ = 0.08241 × exp(0.02869 × DMI) | –86.1 | 0.03 | 0.85 | 0.01 |
| EMPSc | Ŷ = 30.1485 | 2,475 | 46.2 | — | >0.05 |
AIC = Akaike information criteria; MSE = mean square error.
aVolatile fatty acids.
bNon-ammonia nitrogen.
cEfficiency of microbial protein synthesis, calculated as g of bacterial nitrogen/kg of organic matter truly digested.
d P value of the model.