Dairy Herd Management Practices Focusing on Preweaned Heifers, April 1991-July1992. National Dairy Heifer Evaluation Project, July 1993

摘要

A National study of preweaning heifer health and productivity, the National DairyHeifer Evaluation Project (NDHEP), was conducted by the National Animal Health Monitoring System (NAHMS), USDA:APHIS:Veterinary Services, from April 1991 through July 1992 representing herds of 30 or more milk cows and heifer-rearing operations in the participating States. The sample was statistically designed to provide inferences about the national heifer population.