Day by day
Day -21 · Start of close-up
Foetal growth and colostrum preparation increase demands while rumen space starts to shrink. The close-up diet is the bridge between the dry-cow and the lactation ration.
Day -14 · Two weeks before calving
Intake tends to decline gradually. Keeping intake steady limits fat mobilisation before calving.
Day -7 · Last week
Intake falls further; the calcium system prepares for a sudden outflow. Avoid group moves and other stressors close to calving where possible.
Day 0 · Calving
Colostrum and milk suddenly draw large amounts of calcium and glucose; intake is at its lowest. This is when hypocalcaemia risk peaks (Goff, 2008).
Day +3 · Day 3
Milk rises quickly; energy balance is negative and fat mobilisation is high. Early recovery of intake is one of the most important goals of fresh-cow management.
Day +7 · Day 7
Intake rises but lags behind milk; the liver handles a large NEFA load. When NEFA uptake exceeds oxidation capacity, ketones and liver fat tend to increase (Drackley, 1999).
Day +14 · Day 14
Rumen adapts to the higher-energy diet; intake continues to rise. Rapid ration changes now can raise acid load in a rumen that is still adapting.
Day +21 · Day 21
Most cows are moving towards peak intake; energy balance improves gradually. Problems in the first three weeks often show up later as lower peak yield and fertility issues.
DCAD layer
Dietary cation–anion difference (DCAD) compares the main cations (Na, K) with the main anions (Cl, S). Lowering DCAD in the close-up diet induces a mild metabolic acidosis, which is associated with a better calcium response around calving (Goff, 2008). Urine pH is commonly used to monitor this.