Which of the following is NOT a major factor to consider when evaluating halter horses in a contest setting?

When evaluating halter horses in a contest setting, factors such as conformation, movement, and condition are critical because they directly influence the horse's appearance and overall suitability for the breed standards. Conformation refers to the horse’s physical structure, including its proportions and the way its body parts connect, which are essential for breed type and function. Movement is important as it showcases the horse's balance and athleticism, allowing judges to assess its capability and potential performance. Condition relates to the horse's fitness, coat health, and overall presentation, indicating the level of care and training invested.

Manners, while relevant in some competition contexts, do not have the same weight as the physical attributes and health of the horse when it comes to halter classes. In halter competitions, the focus is more on how well the horse exemplifies the breed characteristics rather than its behavior or etiquette. Hence, while manners can play a role in the presentation of the horse, they are not considered a major evaluative factor in the context of halter judging, making it the correct answer to this question.