The effect of age at which spring-born calves are introduced to pasture

Abstract

SummarySpring-born Friesian heifer calves were turned out to grass at either 3 or 4 months of age. In the summer of 1976 the experiment had 20 calves per treatment and in 1977 there were 22 calves per treatment. The calves remained outside for both day and night. They were the leaders in a leader–follower rotational grazing system based on nine paddocks. The followers were yearling heifers and sheep. Each calf was offered a daily grazing supplement of 1·8 kg concentrates. Housing was in mid-September.There were no management problems and summer growth rates were within the range 0·55–0·74 kg/day. Calves turned out at 3 months of age grew slightly better than calves turned out at 4 months. This difference was not statistically significant, but it does suggest there is no harm in turning calves out at an early age. From a practical viewpoint the result indicates that all spring-born calves could be turned out in one batch in early summer.