Jill, that's SO much more, and so much more interesting, than either of us
could have imagined! Thanks you very much!
A L P
Jill wrote:
a_l_p wrote:
A friend sent me the following query. I looked blankly at the screen
for an instant and then the answer - well, the route to the answer -
came to me: sci.agriculture.poultry!
"Do you know what cross it is to produce either, Highline, ross brown
or a brown shaver chook?. they are all very similar. Identical in
fact. A guy I know thinks it is a Leghorn rooster over a rhode island
red. or is it the other way," enquired my friend.
They are a VERY long way from being any direct cross of anything now.
In the 1950's when the demand for eggs worldwide rose steeply after the
wars and the general health of the national commercial mostly ranging
flocks was very very poor indeed, the industry took themselves in hand
In all the strong breeding countries the same things happen -- the egg
industry has been global for over 100 years and there was much to be
shared.
The best birds from the available flocks were brought indoors to vast
breeding centres.
In this way the maximum output of the birds could be produced but more
importantly their health could be controlled very effectively.
First of all birds were tested for the major problems of the time --
salmonellaa, mycoplasmas etc.
Carriers were culled.
Then the productivity of the birds were tested.
The worst were culled
Then the breeding started in earnest. In the mix would have been
predominantly RIR and Leghorns as they were the predominant commercial
breed before.
Millions of birds were bred and over the next 10 years the various lines
were developed
This continues to this day
There are highly intensive breeding programmes all around the world where
the productivity and efficacy of the lines are being tweaked
High on the agenda at the moment are, for instance:
- improving shell quality because there is too high a percentage of eggs
having to go into the non-shell sector due to cracking and too high a
percentage of egg peritonitis before they are spent.
- bringing start of lay ever earlier - they have some strains that will
start at 15 weeks old but its not stable yet
- feed efficiency -- laying more but eating less, and also laying well
on cheaper feeds.
In different parts of the world there will be programmes to cope with
climate problems and the feed that they can get. Although the world wide
shipping of most basic constituents means that much of this is similar
around the globe. China is becoming increasingly dominant in their import
of all feedstuffs.
To achieve their aims there are millions of birds kept as great great
grandparent stocks from which they hope to breed gems of genetics,
depending on what they are looking for. These GGGrandparents are not a
pure breed either but will resemble more RIR type stocks or Leghorn type
stocks.
Pure breed stock may be added to small flocks to inject certain
features -- like improved shell quality.
A trace of this genetics is then put into the next generation and so on
down the line until you have the parent stocks which are still the
athletes but with the new improved feature in their system
[very oversimplified
]
Things like the Black Sex link or the Red Sex link are crosses of
production strains of pure breeds.
