There is increased interest in out-wintering systems which have the potential to reduce costs and hence increase farm profitability. Out-wintering also offers the potential to increase herd size, within the constraints of Nitrate Vulnerable Zone (NVZ) restrictions without the substantial capital costs associated with waste storage. The majority of out-wintering research has focused on kale and its utilisation by dry dairy and suckler cows where relatively modest performance levels are required. In a comprehensive review on forage brassica for out-wintering stock (MDC 2007) it was stated that “despite the developments in New Zealand in the use of brassica based out-wintering systems for dry dairy cows, there seems to be no detailed studies on the use of these systems for growing (0.7-0.85kg daily live weight gain [DLWG]) dairy heifers”. The objective of this experiment was therefore to evaluate the performance of replacement dairy heifers either housed or out-wintered on forage brassicas (stubble turnips).