f Experiment Station Bulletin.)]

129. Beef.--About one half of the weight of beef is water; the lean
meat contains a much larger amount than the fat. As a rule, the parts of
the animal that contain the most fat contain the least water. In some
meats there is considerable refuse, 25 to 30 per cent. In average meat
about 12 per cent of the butcher's weight is refuse and non-edible
parts.[44] A pound of average butcher's meat is about one half water,
and over 10 per cent waste and refuse, which leaves less than 40 per
cent fat and protein. Meat is generally considered to have a high
nutritive value, due to the comparatively large amounts of fat and
protein. Beef contains more protein than any vegetable food, except the
legumes, and from 1 to 1.5 per cent mineral matter, exclusive of bone.
Some of the mineral matter is chemically united with the protein and
other compounds. While figures are given for average composition of
beef, it is to be noted that wide variations are frequently to be met
with, some samples containing a much larger amount of waste and
trimmings than others, and this influences the percent of the nutritive
substances. In making calculations of nutrients consumed, as in dietary
studies, the figures for average composition of meat should be used only
in cases where the samples do not contain an excess either of fat or
trimmings.[45] When very lean, there is often a large amount of refuse,
and the meat contains less dry matter and is of poorer flavor than from
animals in prime condition. In the case of very fat animals, a large
amount of waste results, and the flavor is sometimes impaired.

130. Veal differs from beef in containing a smaller amount of dry
matter, richer in protein, but poorer in fat. Animals differ in
composition at different stages of growth in much the same way as
plants. In the earlier stages protein predominates in the plant tissue,
while later the carbohydrates are added in larger amounts, reducing the
percentage content of protein. In animals the same is noticeable. Young
animals are, pound for pound, richer in protein than old animals. While
in the case of vegetables the increase in size, or rotundity, is due to
starch and carbohydrates, in animals it is due to the addition of fat.
But plants, like animals, observe the same general laws as to changes in
composition at different stages of growth.

[Illustration: FIG. 28.--STANDARD CUTS OF MUTTON.

(From Office of Experiment Statio