Effects of weaning period length on growth and health of preconditioned, spring-born beef calves originating from the Great Plains. I. Conventional weaning ages 1 1 Contribution no. 14-345-J from the Kansas Agricultural Experiment Station

Spring-born Angus×Hereford calves (n=433; average initial weight=229±37kg) were assigned randomly to treatments that corresponded to a length of time (d) between separation from their dam and transport to a feedlot: 60, 45, 30, 15, or 0 d. Weaning date varied by treatment; transport occurred on a common date and at a common age (220±22 d) for all treatments. Calves were vaccinated against common diseases 14 d before maternal separation and again on the day of maternal separation. Calves were transported