Improving pedigree prediction, sire, and cow evaluation by adjusting production data for past reproductive performance

Abstract

REVIEW OF LITERATURE Days Open The antagonistic relationship between number of days open (days from calving to conception) and cumulative milk production is obvious, but the cause and effect relationship is still unclear. Several studies indicated that higher 305 day milk yield was the cause of more days open (Suchanek and Drovacek, 1960; Morrow et al., 1966; Spike and Meadows, 1973; Spalding et al., 1975). While other studies indicated that more days open was a cause of higher 305 days milk