CHANGE IN BODY CONDITION SCORE OF HOLSTEIN COWS AS AFFECTED BY PARITYAND MATURE EQUIVALENT MILK-YIELD

Cows from 25 dairy herds were scored for body condition at 3-mo interv als for over 2 yr to study the pattern of changes during lactation and the effects of parity and milk yield capability of cows on changes in body reserves. Data were recorded for 1395 Holstein cows grouped into three parity classes and five classes of mature equivalent milk yield . The analysis model accounted for nearly 70% of the variation in body condition score. Body reserves decreased during early lactation until about 100 DIM and were restored during mid and late lactation. The pa ttern of change in body condition score varied among lactations and da iry merit of cows. Depletion and subsequent recovery of body reserves were less intense for primiparous cows than for multiparous cows. Loss of body condition scores was higher and more prolonged for cows of hi gher dairy merit. The minimum body condition score occurred at 3 mo af ter calving for the worst yielding cows and at 4 mo after calving for the best yielding cows; the highest yielding cows had twice the loss i n body condition as the lowest yielding cows. General equations are pr esented as a proposed guideline to examine changes in body condition s core of Holstein cows of different parities and dairy merit.