Which aspect reflects a breeding gilt's overall body quality?

The curvature of the rib is a critical aspect that reflects a breeding gilt's overall body quality because it directly relates to the animal's capacity for growth, muscle development, and fat distribution. A well-curved rib indicates a more developed rib cage, which allows for better lung capacity and overall health. This can also correlate with better feed efficiency and reproductive performance, making it an essential trait to evaluate in breeding stock.

While thickness of the legs, ear length, and coat color can provide some information about an animal's conformation and health, they do not offer the same comprehensive indicator of overall body quality as rib curvature. Leg thickness is important for strength and mobility, but it is not as directly tied to internal capacity and growth as rib curvature is. Similarly, ear length and coat color are often more subjective traits that may not significantly influence the animal's performance or productivity in breeding. Thus, curvature of the rib serves as a more reliable means of assessing the overall body quality of a breeding gilt.