The use of zoometric measurements of cows for determination of rump conformation and course of parturition.

a total of 900 polish Black-and-white holstein-friesian (phf) cows with at least 75% hf blood and the mean yield of over 6000 l milk were kept in a loose barn at the chorzelow experimental station of the national research institute of animal production. zoometric measurements of the cows were made 26–30 days (28 days on average) before calving. The aim of this study was to show rump conformation traits that are critical to rump angle and the course of parturition, and to test the possibility of using these traits in conformation indices and breeding work. The results showed that the change in rump angle from raised rump to sloping rump was paralleled by a steady decrease in height at pins and thurls by an average of 0.45 to 0.58 cm for each degree of rump angle. among the traits of external pelvic measurements, the greatest effect on calving ease was exerted by a set of measurements describing both the width of hips and pins and the height of thurls and pins. The conformation indices based on the differences in height between hips and thurls and between pins and thurls were the most reliable in predicting easy calvings. The body conformation indices analysed can be successfully used to determine rump conformation and course of parturition.