Rigor mortis and thaw rigor in lamb

Abstract The onset of rigor mortis in the longissimus dorsi muscle of the lamb has been studied, with particular emphasis on the effect of temperature on its time‐course. With the introduction of faster‐freezing techniques in the frozen lamb industry, part of the carcass may be frozen before the onset of rigor mortis. It is shown, however, that the extreme shortening and loss of ‘drip’ characteristic of thaw rigor in isolated muscles will not occur if the muscles remain attached to the skeleton and thawing is not accelerated.