Final answer:
The restraint method not commonly used in laboratory swine is perch. Swine are typically restrained using methods such as a snare, tunnel, and rump grasp, which are tailored to their behavior and physical capabilities.
Step-by-step explanation:
The method of restraint not commonly used in laboratory swine is d) Perch. Restraint methods for swine typically include the snare, which is a looped instrument used to hold the animal by the snout, and the tunnel, which is a confined space that restricts movement.
Another common method is the rump grasp, which involves the handler holding the pig around the pelvic area to limit mobility. Perching, on the other hand, is associated more with birds and not used for restraining pigs, which are not adept climbers and do not use perches.