Which of the following is NOT a method of dehorning animals?

Trimming is not typically recognized as a dehorning method. Dehorning refers to the removal or destruction of the horns of an animal, and the other methods listed—burning, cutting off, and using acid—are all established techniques for achieving this.

Burning involves the use of a heated instrument to damage the horn area, thus preventing the horn from growing back. Cutting off simply refers to the surgical removal of the horns, while using acid, such as a caustic paste, can effectively kill the horn-producing cells at the base of the horn. Each of these methods serves the same purpose in controlling or eliminating horns and can be done at different stages of the animal's growth.

In contrast, trimming typically refers to the act of shortening or shaping the horns rather than removing them entirely. While trimming may be done for aesthetic purposes or to manage certain health considerations related to horns, it does not constitute dehorning in the sense of completely eliminating horn growth. Therefore, this distinction clarifies why trimming is not classified as a dehorning method.