Agripedia

An animal's degree of leanness is influenced by its degree of muscling, its frame size, its sex, and its age and weight. Leanness should only be viewed after muscle has been evaluated. The assumption that heavy muscled hogs will be lean and light muscled hogs will be fat is normally true except in situations of extreme weight or extreme lack of frame size. Because gilts mature at a later age (or at a heavier weight) than barrows, they will be leaner than barrows if compared at the same age or weight. It is also important to remember that fat will be deposited from the front of the animal to the rear. Fat will first be deposited in the checks and jowl, then behind and over the shoulders, then in the flanks, and finally around the tailhead.

Leanness is best evaluated by looking for indentations over and behind the shoulders and at the ham-loin junction, and by looking for the presence of a dimple just in front of the tailhead. When an animal is lean it will have a neat, trim, tight jowl and underline, and you will be able to see the shoulder blade work just under the skin when it walks. A couple of key points to remember is that muscle will be hard and firm, while fat will be soft and loose.

The white pig on the left is very smooth over its top and loose and wasty in its crotch indicating it is too fat. You should notice that this pig is wider over its top than it is at its base. This should also raise a red flag that this pig is too fat. The belted pig on the right also gives several indications that it is too fat. Note the smoothness over the shoulder and the lack of definition in the ham-loin junction. This pig is also wasty and loose in its jowl and checks, loose in its flanks, and lacks a dimple in the front of its tailhead.

This picture illustrates a pig that is extremely lean. It is clean over its shoulder and loin, clean and firm in its flanks, has a well-defined ham-loin junction, and is clean and firm in its crotch. This pig is a lean, mean, heavily muscled machine.