Beef and Lamb New Zealand has made some major overhauls to the
Sheep Improvement Limited (SIL) genetic engine in recent years and reworked
some breeding values and indexes. Many of these I agree with, some I don't and
some I think are just a waste of time.
In general, I support most of what it is trying to achieve. As I
have reiterated many times if you have a good understanding of the issues and
problems with the SIL engine and figures, then you are in a position to utilise
those breeding values and indexes that are accurate to assist you in breeding a
better sheep.
However, SIL breeding values and genomic breeding values are not
the panaceas that will allow you to breed the ultimate sheep. In my case I have
often culled my top ranking lambs on SIL, as while their figures may be high,
they are simply not fit to breed from.
This year my number one ranked ram hogget is a very good sheep,
but in my experience, it's hard to find a top ranking ram that is also a good
sheep and believe me, I have done some looking. The point is that to breed a
good ram you have to be a good stockman and ensure you maintain the
fundamentals so that five, 10 and 20 years down the track your productivity
continues to improve. If you don't, you will go backward and fast.
Unfortunately, there are a lot of breeders who either place far
too much emphasis on figures alone or quite simply don't have the stockmanship ability to ensure that
the rams they are putting up for sale are indeed sound.
I know that Beef +Lamb NZ do acknowledge that stockmanship plays a significant
role in breeding sheep. To this end, it is assisting in developing a stockmanship video that will be a
training tool for many generations to come. It will ensure that those breeding
sheep will not only understand indexes and breeding values but also breed
animals that are sound and fundamentally correct to make sure that the
productivity graph continues to rise, or at least not go backwards.
Given the above, I was stunned when Beef + Lamb recently
started marketing to breeders via email and to the general sheep farming
community in agriculture magazines saying "every ram sold by a SIL breeder
now has a single index figure-one number that's comparable across all rams of
all breeds." The higher the number, the better the ram.
Honestly, this is absolute b....... and just because a ram has a
higher figure doesn't mean it's a better sheep, all it means is that one index
is greater than the other. Everything else being equal between the two, you
would, of course, take the higher index.
Secondly, for an index to be reliably compared between different
breeders and different breeds, you need an excellent linkage between breeders
and groups all around the country on all the traits contained in the index. The
better the linkage the more reliable the comparison. You may, in fact, have
good linkage regarding growth rates, but poor on survivability, for example.
In any event, the reality is that a lot of rams sold come from
flocks (around 50 percent, possibly slightly more) are not sufficiently linked
to everyone else to enable these indexes to be compared with rams from another
flock. Its meaningless and misleading to
suggest otherwise. You don’t know if the
higher index reflects good genetics or simply good linkages because you need to
be well linked to get high indexes and breeding values. You can of course compare rams within a flock
but not against others.
I wish Beef + Lamb would first limit itself to providing a
service to breeders instead of being a marketing entity which cynically is done
to justify its existence. Secondly, I hope it ensures that what it does say
comes with the necessary caveats to be correct because, with the money they
have, the wrong message could have a very detrimental effect on the sheep
industry.
