What is a rarely used method for sampling livestock due to its destructive nature?

The method of excision is rarely used for sampling livestock because it involves removing a portion of tissue from the animal, which is a destructive approach. This technique is typically employed when specific internal tissue needs to be analyzed, possibly for disease diagnosis or other specific testing purposes. However, because this method directly impacts the health and wellbeing of the animal, it is not frequently used, especially in contexts where non-destructive sampling options are available.

Other methods, such as sponging or random sampling, focus on collecting samples without causing harm to the animals, thereby preserving their health. Sponging can entail collecting bodily fluids from the exterior without the need for incision, while random sampling usually involves selecting animals to represent a larger population without causing any destruction to their physical form. The moving window method, while a statistical approach, does not involve actual sampling of the livestock itself. Therefore, excision stands out as the only method with destructive consequences, limiting its use in practice.