To evaluate longevity, milk production, and breeding performance in adult Holstein cows fed either a plasma-derived commercial colostrum replacer (CR) or raw bovine maternal colostrum (MC) at birth.
Randomized controlled clinical trial.
497 heifer calves born in 12 commercial dairies located in Minnesota and Wisconsin.
All calves were separated from their dams within 30 to 60 minutes after birth and systematically assigned to be fed either MC (control group [n = 261 calves]) or CR (treatment group [236]). Calves were observed from birth up to adulthood (approx 54 months old), during which time death and culling events plus milk yield and breeding performance data were collected. Time to death, time to culling, time to death or culling combined, time to first calving, and time to conception intervals were evaluated by use of proportional hazards survival analysis models. Number of times inseminated per conception and lifetime milk yield (up to 54 months old) were evaluated by use of general linear models.
Cows fed CR as calves at the time of birth were no different than cows fed MC as calves with respect to overall risk of death, culling, or death or culling combined (from birth to 54 months of follow-up and from first calving to 54 months old); lifetime milk yield; and breeding performance.
No difference was detected in overall risk of death or culling, milk production, or reproductive performance between cows fed CR and those fed MC as calves at birth.