WINTER 2018 UPDATE
Performance Recording in Drought Conditions
M
any regions of Australia have received below average rainfall throughout autumn and winter 2018. Given the seasonal conditions, we thought it would be
Consider the weights of the 12 animals shown in Table 1. In
timely to discuss some of the issues that come up in regards to
range from 398 kg (Animal 4) to 328 kg (Animal 10); there are
recording performance information in drought conditions. This
a number of animals that have performed above the average of
article will discuss whether performance information recorded
the contemporary group, and a number of animals that have
under drought conditions is valid for genetic evaluation purposes,
performed below the average of the contemporary group.
a non-drought year, under normal seasonal conditions, the average 200 day weight of these animals is 360.6 kg. The animals
Generally speaking, we would expect animals that perform above
and outline some of the trait specific considerations that beef
the average of the contemporary group to have 200 Day Growth
producers should consider if continuing to collect performance information under challenging seasonal conditions.
EBVs that are above their mid parent value, and animals that
Can I Still Record Performance Information in a
200 Day Growth EBVs that are below their mid parent value.
perform below the average of the contemporary group to have
Drought?
Now consider the weights of the 12 animals shown in Table 2.
Yes. Many producers are worried that lighter weights on
In a poor year, under drought conditions with limited feed, the
their animals will lower their EBVs, but this is not the case.
average 200 day weight of these animals is 255.9 kg. While the
BREEDPLAN analyses animals within contemporary groups;
weights are lower than they would be in a non-drought year, we
that is, animals that have had equal opportunity to perform. It is
still see a spread in weights, with the heaviest animal weighing
not the raw weight of an animal that is important, but rather how
295 kg, and the lightest animal weighing 223 kg. As was the
that animal has performed relative to the rest of its peers.
case in the non-drought year, some animals perform above the
SBTS & TBTS provide a national extension network for genetic technologies for the Australian beef seedstock industry 1