Free Water Intake Equations for Dairy Cows
Cow Status | Equation |
|---|---|
Lactating cows | |
— Equation 1 | FWI (L/d) = −91.1 + (2.93 × DMI) + (0.61 × DM%) + (0.062 × NaK) + (2.49 × CP%) + (0.76 × Temp) |
— Equation 2 | FWI (L/d) = −60.2 + (1.58 × Milk) + (0.064 × NaK) + (0.83 × DM%) + (0.54 × Temp) + (0.08 × DIM) |
Dry cows | |
FWI (L/d) = (1.16 × DMI) + (0.23 × DM%) + (0.44 × Temp) + (0.061 × [Temp − 16.4]2) | |
Abbreviations: CP%, dietary crude protein (% dry matter); DIM, days in milk; DM%, dietary dry matter content; DMI, dry matter intake (kg/d); FWI, free water intake; Milk, daily milk yield, kg/d; NaK, sum of dietary Na plus K (mEq/kg dry matter); Temp, dairy mean ambient temperature (°C). | |
Adapted, with permission, from National Academies of Science, Engineering, and Medicine (NASEM). Nutrient Requirements of Dairy Cattle. 8th rev ed. The National Academies Press; 2021. doi:10.17226/25806 | |