Dynamic end-to-end service provisioning is critical to satisfy various user and carrier requirements such as Bandwidth-on-Demand and Dynamic Bandwidth Adjustment in SDN-enabled OTN over WDM networks. In this context, Service Provisioning Time (SPT) is one of the important metrics, especially in highly dynamic traffic scenarios. In this paper, we propose the Resource Delayed Release strategy to improve the SPT performance by delaying the release of an optical channel when the channel no longer carries any services. Simulation results show that as much as 45 90% of the SPT is reduced by using RDR strategy under different traffic scenarios, and the blocking probabilities of service requests are also reduced.