Software-Defined Networking (SDN) is a recent technology that makes a breakthrough into the computer networking world. SDN has a significant role in network optimization and performance improvement. The main SDN concept is separating both the data and control planes which allows network programmability and flexibility. Since the current traditional network cannot endure more user needs, we apply different load balancing strategies to distribute the user requests among a number of servers. In this paper, we propose two OpenFlow-based approaches for dynamic server load balancing in SDN environment. Hence, we implement ``CPU-based'' and ``CPU-Memory-based'' load balancing techniques and evaluate their performance compared to the static Round-robin and random-based load balancing techniques using Ryu OpenFlow controller. The results show that the proposed schemes achieve more reliability and higher resource utilization than the Round-robin and random-based load balancing strategies. In addition, they have a lower response time and higher transaction rate and throughput. The proposed schemes exhibit more scalability and low-cost characteristics.