A loss of one body condition score during the first two to three weeks of lactation is extremely fast and indicates a feeding problem. A loss of one-half body condition score in four to five weeks is normal and indicates proper, effective herd management. Body Condition Score, Energy Balance, and Milk Production High-producing dairy cows simply cannot consume enough feed during the first 60 to 90 days of lactation to support high milk yields and avoid weight loss. Body fat must be mobilized to support high milk production. Energy balance is the difference between intake of feed energy and energy output in the milk.
Energy balance is related to body condition loss or gain.
Maximum negative energy balance occurs within two to three weeks after calving, and cows may reach positive energy balance by approximately 60 days in milk. A primary goal is to manage the feeding program to properly manipulate body condition loss and minimize the duration of negative energy balance. High milk yield does not cause excessive weight loss if the feeding program is well-tuned. Two or three times daily milking does not alter target body condition scores. Body fat appears to inhibit feed intake so cows fat at calving cannot reach maximum feed intake until they lose some of the excess conditioning.