RELATIONSHIPS OF BODY CONDITION SCORE TO PRODUCTION VARIABLES IN HIGHPRODUCING HOLSTEIN DAIRY-CATTLE

Practical relationships were determined between milk production, healt h, and reproduction with the amount and use of body fat in high produc ing lactating Holstein dairy cattle. Approximately 350 cows and heifer s >15 mo of age in a high producing herd were assigned body condition scores at monthly intervals for 24 mo. Production of 305-d FCM average d 9541 kg (range 8826 to 10,818 kg). Body condition score at each of f our calvings at 30, 60, 90, 120, and 305 DIM in each parity and loss i n score in each lactation were summarized. Multiple regression related scores to milk and milk fat production, reproduction, and disease var iables within and among lactations. No difference in score occurred at calving or at dry-off among parities. The range of body condition sco res was less than is commonly reported; however, loss of condition inc reased with increasing parity from .3 in first lactation to .9 body co ndition score units in lactations greater than or equal to 4. The body condition score varied quadratically with DIM but, at a given DIM, wa s not related to the daily milk production on that DIM. Parity had a s tronger relationship with milk and milk fat production than did body c ondition score. However, within lactation, body condition score at cal ving and the loss of score were related quadratically to milk producti on. No significant relationships of body condition score to the incide nces of pyometra, metritis, retained placenta, cystic ovarian disease, AI per conception, days to first AI, or dystocia existed in this herd .