Members List - NZ RED DEVON CATTLE BREEDERS ASSOCIATION

If the Dam is A1A2 and she is mated to an A1A2 Sire then 25% of the offspring
will be A1A1, 25% of the offspring A2A2 and 50% A1A2. You will always
have to test the offspring with this type of mating to find out what you got!
The slowest way of breeding up to an A2A2 herd would
be using a known A2A2 bull every year for about 20 to
50 years in succession and not test any dam as some of
these Devon cattle are still calving in their late teens!
Eventually you will have an A2 herd.
To speed up the change to an A2 herd (short of resorting
to embryo transfer methods) the next best method is to
use the known tested A2A2 bull AND test all your dams.
If at all possible, find a reason to sell or cull all the A1A1
dams. Have a look at the A1A2 dams and if there are any
faults there then sell or cull. All the A2A2 dams you
have should be bred from if you are happy that they are
good breeders. This is how our approach has been and
when we initially tested our breeding Devon cattle. We
only had a choice of two cows that were A2A2 so of
course we couldn’t cull them! With our dairy herd we
have let natural attrition remove the A1A1 and A1A2
cows over time and a handful who were excellent milk
producers, early calving and sound in the udder have
lingered in the herd. It has taken us over 10 years with
our dairy herd to get an A2 herd but we still have old
girls left and knowing the longevity of the Devon breed
this might take 20 to 50 years but I do believe it would be
a prudent idea to start breeding in that direction now if
only to keep up with what our trading partners are doing.
Ignoring the A2 issue may eventually condemn the
Postscript
I have today 5/6/12 spoken with Professor Woodford to
ask about several of the issues I have raised in this item
regarding the A2 issue in Devon’s. He still stands by
the information written in the book he wrote – The Devil
in the milk printed in 2007. Now, however there is even
more science coming out of Poland and Russia that is
only just now being translated into English that is also
backing up some of the more contentious issues. His
exact words to me about the A2 and tenderness issue is
that he “would not be surprised if there was an
association with A2 and tenderness’ but he believes ‘it
could be a loose association and it could even be related
to the omega 3 fat content” as there have been
suggestions that A2 cows produce a higher level of the
omega 3 fats in the milk. But he has not seen sufficient
evidence to want to make that claim. It may be because
there is a gene, located close to the beta casein gene,
which influences omega 3 levels in the milk. However,
the association between the allele (variant of the gene)
influencing omega 3 levels and the A2 allele may not
hold across all populations. Similarly, if there is a link
between A2 beta casein and tenderness in meat this may
or may not hold across all populations. He doesn’t think
he has seen any evidence linking the A2 allele to omega 3
in meat.
He will not make any statements about A2 and tenderness
or the potential A1 meat issues until there is good
Sire
A1 A2
Dam A1 A1A1 A1A2
A2 A1A2 A2A2
Devon breed if it is predominantly A1 as I currently fear
the breed to be.
For those who are interested our little Hau Hiwi Devon
stud (which was down to 14 after the drought years) was
fortunate to have two cows that were A2A2. One cow
(born 1999) was from the Taylor stud dispersal and her
Dam was Taylor Ali’s Viola and her Sire was Valley
Brook 34/96 and the other cow came from the
Woodlands stud (born 2001) and her Dam was
Woodlands Joy 7th and her Sire Rotokawa 861 so we
know from the genetic lesson above that each of these
Dams and Sires had a least one A2 allele! So if you
check the ancestry of your cattle and you see any of these
names there is a chance you will have at least one A2
allele somewhere in the genetic make-up of your herd!
If my memory is correct we started testing the Devon’s
for A2 in the mid 2000’s and we now have 25 females –
14 of whom are A2A2 and the rest A1A2 and three bulls
born in 2009 who are A2A2. A2A2 semen is now
available from one of these bulls Hau Hiwi 09-905.
Disclaimer:
I have no financial interest in A2 Corp.
Louise McConnell
Veterinarian
scientific research to validate claims and he is not aware
about anyone doing research in these specific areas. He
mentioned that the A2 allele is very high in the Nelore
breed and these Nelore (of which there are a great
number in Brazil; he thought it was the dominant breed)
are not particularly tender. So this illustrates that within
a breed it may be that the A2 animals are tenderer but
between breeds other factors can dominate.
He is not convinced about A1 meat being injurious to a
portion of the population as A1 milk has found to be. To
his knowledge the BCM7 arising from A1 milk is an
expression of the gene that is only directly expressed in
the beta casein protein part of the milk and is not part of
meat.
If you wish to contact me to clarify points raised here
then call me at 078677573.
A2A2 reference material – websites
http://www.a2corporation.com
http://www.betacasein.net/research.pdf
http://keithwoodford.files.wordpress.com/2011/
06/milk-proteins-and-human-health-woodfordgpce-may2011-final1.pdf