Which restraint device is specifically designed to place an animal on its side?

The casting rope is designed specifically for restraining an animal in a way that allows it to be placed on its side. This device is typically used in veterinary procedures or situations where it's necessary to immobilize the animal for examination, treatment, or surgery.

When the casting rope is applied correctly, it allows the handler to safely roll the animal onto its side without causing undue stress or injury. This positioning is often advantageous for certain procedures that require better access to the animal's body.

In contrast, other restraint devices serve different purposes. For example, a cross tie is primarily used to secure a horse's head to prevent movement while grooming or handling, while stock yards are designed to contain animals within a designated space. Hobbles can restrict the leg movement of an animal but do not assist in laying the animal down in a controlled manner. Therefore, the casting rope stands out as the most appropriate device for achieving the desired position of placing an animal on its side.