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VikingNews UK 02 2016
16 / 24
genomic selection has come to stay to increase the
genetic
progress and at the same time, it gives us the ability to identify
genetic
defects
with recessive inheritance.
genetic
disorders such as the complex vertebral malformation (cvm) and leukocyte adhesion deficiency (blad) have had significant economic impact on dairy cattle breeding world- wide. these well-known
defects
have been found in abnormal calves. recessive
defects
will only be visi- ble when you have two defect genes (aa). both humans and animals are car- riers of a whole lot of recessive
defects
that we are not aware of, because if you have an aa, you don?t notice it. with genomic selection we know a whole lot more ? and if we find that we have an ?aa? gene, we can be sure that we also have the ?aa? combina- tion. therefore, it is very important to be able to evaluate the defect one by one and take decisions about how we will handle it in the best way, without com- promising with ethics. if we want to extinct all
defects
that we have not been aware of until now, we are risk- ing losing in
genetic
progress dramati- cally.
genetic
defects
in genomic era by lars nielsen, head of breeding, viking
genetic
s 80 different flushing
bulls
in one year when we select
bulls
to our flushing contracts, we want to use as many dif- ferent as possible. we make a good mix of our own viking
bulls
, but we are also using the best ones from other coun- tries, based on the nordic total merit (ntm) scale. the average ntm of the 80
bulls
we have used last year is +34 in ntm, and that makes the next gener- ation very promising. it is still a wish not to flush the top heifers only with the top indexed
bulls
, but to use a wider range of all selected sires of sons in our line up so by using all recommended sire of sons, we make a better
genetic
progress. in table 1, you can see the
bulls
most used for flushings. deciding on flushing bull three weeks before insemination for most of the flushings we use doses from the very youngest
bulls
, to keep the generation interval as short as pos- sible, to get the highest
genetic
pro- gress and because owners of the heif- ers also want to have the first doses of a new top bull! therefore, to have the newest bull, wait as long as you can before the flushing, to get the perfectly matched bull. by claus langdahl, breed coordinator vikingholstein table 1. most used
bulls
in contracted flushings in viking
genetic
s last year. bull no. of flushings gntm vh sherman 12 +37 ev jetset 12 +37 vh broback 11 +44 vh bolus 11 +39 vh ramis 10 +37 vh broback (balisto x vh mandel). drinking from an australian creek 16 vikingnews | june 2016
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