Abstract: In order to facilitate cutting of the abdominal skin of the carcass, the skin is stretched to a taut condition just prior to commencing a cut of the skin. In a preferred embodiment, such stretching is accomplished through the use of a cam-actuated flapper plate that engages the skin and draws it toward one leg of the carcass, maintaining it in such taut position throughout the cutting process. In an embodiment used for making an opening cut to the body cavity, the knife swings along a skewed path of travel relative to the line of symmetry between the backbone and keel bone of the carcass so as to produce an angled cut that avoids nicking the keel bone.