Extending Incomplete Lactation Records of Holstein Cows with Varying Levels of Production

Abstract

~onthly test-day records from 4,361 Holstein cows were studied to determine if age, season of freshening, level of peak production, and days open affected the precision of predicted factors used in extending incomplete lactation records, and to develop improved regression equations or ratio factors for predicting complete lactation records from Dairy Herd Improvement Association cumulative month records.