The landing gear had been selected down during descent to the destination. On arrival overhead the strip the pilot noticed some cattle on the strip. He became concerned with the onset of darkness and selected the gear up to make a quick pass to clear the cattle from the strip. The gear was selected down on downwind and the selection was again checked on final approach, but the aircraft landed without the gear being down and locked. Inspection of the aircraft revealed that the landing gear actuator motor drew excessive current due to the armature windings being badly burnt. This resulted in the landing gear circuit breaker being tripped during the retraction sequence and the gear stopping just before the fully retracted position. When the pilot selected the gear down before landing, the gear remained in its previous position. With the gear in this position, neither gear position indicator lights was illuminated.