The officers of a cooperative shall consist of a president, vice president, secretary and treasurer, who shall be elected annually. No person shall continue to hold the offices of president or vice president after he shall have ceased to be a director. The offices of secretary and of treasurer may be held by the same person and need not be a member of the board of directors. The board of directors may also elect or appoint such other officers, agents, or employees as it shall deem necessary or advisable and shall prescribe the powers and duties thereof. Any officer may be removed from office and his successor elected in the manner prescribed in the bylaws.