the meat of a lamb is taken from the animal between one month and one year old with a carcase carcass in american english weight of between 5 5 and 30 kilograms 12 and 65 lbs this meat generally is more tender than that from older sheep and appears more often on tables in some western countriesamb is the most expensive of the three types and in recent decades sheep meat is increasingly only retailed as lamb sometimes stretching the accepted distinctions given above the stronger tasting mutton is now hard to find in many areas despite the efforts of the mutton renaissance campaign in the uk