This experiment has shown that the principal advantage gained from the supplementary
feeding of early weaned lambs, grazing good
quality pasture, is that they reach a heavy
market weight quicker than lambs given none.
The additional gain of 2.8 - 3.8 lb.,
obtained during the period from 13.7 to 14.9,
requiring 52.9 lb. of feed, at a cost of 15.2/ -, is unlikely to be economic under most circumstances. Whether this additional expenditure
is recouped or not will be dependent on price
fluctuations for fat lambs and the practical
advantages of earlier sale. This applies only
to the production of fat lambs at 100 lb. liveweight.
The results show that if 90 lb. liveweight
were the minimum acceptable figure then the
advantages of feeding for earlier sale do not
An experiment of this type has limitations
in obtaining an objective assessment of many
factors. For example, saving in time to
slaughter cannot be accurately stated unless
lambs are sent for slaughter in a condition
which can be precisely defined or alternatively
at a specified weight with only some
restriction of condition.
Furthermore, objective information on
carcass quality as affected by supplementary
feed may be best obtained by having all animals
slaughtered within a narrow liveweight range
irrespective of condition. Such an investigation woula only be justifiea if critical carcass
assessment techniques are used. This approach
was not possible in the present experiment.
The differences recorded in carcass quality,
while small and essentially subjective, would
tend to suggest that supplementaïy feeding has
cause a a slightly different growth pattern
resulting in a leaner carcass. This aspect
however would require a more critical appraisal
before a conficent assertion could be made.
Nevertheless, the farmer -is likely to
operate under the circumstances pertaining to
this experiment and the results suggest that
dense, leafy pasture is adequate to maintain
adequate lamb growth, until mid-September, for
fat lamb production.
It may be argued that the supplementary
feed used in this trial would best be replaced
by a high energy mixture and this aspect should
There was no effect of either age or
weight at weaning on subsequent liveweight gain
during the experimental period or during a period of 29 days after weaning. This confirms
the evidence, of the experiment reported
previously, that weaning at 14 weeks is a
satisfactory and practical possibility given
good quality pasture after weaning.