A more robust, easily applied but more subjective method is
to visually assess body condition. This is readily done on large
numbers of animals and, if clear criteria are set for distinguishing
grades of condition, it can be reproducible. Up to five grades are
easily distinguished; it is often claimed that nine or ten grades can
be used by experienced observers but reproducibility within, and
particularly between, observers may be rather poor. The fewer the
grades the more repeatable the grading, but the greater the
differences in body weight corresponding to each change of grade.
Infrequent watering of cattle is likely to superimpose a two or three
lay cycle on liveweights, as also on visual estimates of condition.
Since individual cattle may take in up to 30 litres of water (30 kg
of liveweight) in five minutes one may question the interpretation
of measurements made either before or after watering. In these
conditions heart girth may be a more reliable measure.