Íslenskar landbúnaðarrannsóknir - 01.03.1970, Blaðsíða 22

20 ÍSLENZKAR LANDBÚNAÐARRANNSÓKNIR
58 coat with white flanks, with blaze
60 stockings with head spot or or both nose spot
61 stockings witli blaze
62 white collar and stockings
63 eagle head
70 white collar, without head socks spot and
71 white collar, without head spot, white
socks
80 head spot, no socks
81 head spot, socks
90 socks, no head spot
91 stockings, no head spot
92 dark outer socks, no head spot
With the code defined in the way shown
above, it often proved possible to obtain
information on some of the basic white
markings of an animal just from the nanie
the colour had been described by in the
flock books. If an animal was for example
described as having hood markings, the
first digit in the code for that type of
markings is always 4, while the second
digit gives further information about other
basic white markings together with the
hood. Similarly an animal with a hood and
cloak would always have 5 as the first
digit in the code for white markings, irre-
spective of the otlier basic markings. This
made it possible to recover information
about markings in terms of code numbers
from flock books, even if the code system
had not been in use when the records were
made. On the other hand, tliese older re-
cords were of considerably less value than
records macle after the code system had
been developed. With the code system in
operation, the recording of the white
markings was made as close to the given
code as possible, while the lamb was avail-
able for inspection.
E. NUMERICAL CODE
FOR COLOUR DESCRIPTION
The codes for the rnain colours ancl the
codes for white markings were combinecl
into a 4-digit number, where the first two
cligits showed the rnain colour ancl the
last two digits tlie type of white markings.
The full code number for white colour
was thus 0100, that that for black mouflon
with head spot and socks 0481 and that
for greybrown badgerface 1400 to show
some examples.
When reference is made to code numbers
for main colours in the following, only the
first two digits of the full code number are
used, and code numbers for white mark-
ings refer to the last two digits of the full
code numbers. When a complete descript-
ion of the colour of an animal is needed,
the full code number will be given. The
colour black badgerface with white collar
and stockings will thus be referred to as
colour 0362, etc.
CHAPTER III
Planned breeding experiments
A. METHODS
In earlier studies of colour inheritance in
sheep the techniques usecl for obtaining
information have mainly been of two
types. The first of these is based on obtain-
ing true breeding animals of the colours
under study, as the parental generation. In
the Fx progeny the dominance relation-
ship between the colours is assessed, and