Items2 | LMW | MMW | HMW | SEM | P-value |
---|---|---|---|---|---|
Metabolic weight, kg | 126.3c | 136.4b | 147.8a | 2.89 | 0.026 |
Milk production and composition | |||||
 Milk yield, kg/d | 38.7 | 38.5 | 36.8 | 2.02 | 0.057 |
 Milk fat, % | 3.66 | 3.73 | 3.81 | 0.26 | 0.062 |
 Milk protein, % | 3.22 | 3.28 | 3.37 | 0.29 | 0.059 |
 Total milk solids, % | 12.4 | 12.3 | 12.7 | 1.03 | 0.826 |
 FCM yield, kg/d | 36.7 | 36.9 | 35.6 | 2.34 | 0.068 |
 ECM yield, kg/d | 37.4 | 37.5 | 36.5 | 2.62 | 0.084 |
Carbon dioxide emissions | |||||
 Total CO2, g/d | 18,996 | 19,269 | 19,339 | 20.83 | 0.475 |
 Total CO2/MW, g/kg | 150.6 | 141.3 | 131.1 | 4.03 | 0.063 |
 Total CO2/ECM, g/kg | 517.6 | 530.6 | 546.6 | 9.13 | 0.078 |