GENERAI,:
Available evidence seems to show that the
Scottish Blackface breed is not an indigenous breed
of sheep in Scotland. It has been introduced from
the south and has spread northwards. The breed has
never become successfully established in Caithness
and Sutherland: otherwise it has become the most
numerous and important breed in the remaining mountain-
ous parts of the country. It is probable that its
characters have been influenced by crossing with the
native "dun" - or with the. "white-faced" sheep and the
infusion of this and possibly other blood may explain
in part the differing characters in various districts.
FLEECE CHARACTERS:
The character of the fleece varies in diftferent
districts in Scotland: so much so that definite
areas are associated with the production of various
grades of Blackface wool required for tweeds, carpets
mattresses and so on. The reasons for the difference
between the fleeces of these districts are not obvious
it is suggested however that there may be some areas
where a larger amount of unimproved blood enters into
the compositon of the sheep stocks than elsewhere
and that parasitic infestation and variation in the
mineral and other content of the pasture may collectively
or individually play a large part in this
differentiation.
Climatic conditions per se do not appear
to exert that considerable influence on fleece which
is usually attributed to them.
CROSSING:
The results of crossing with modern breeds
of sheep has been considered and it seems evident
that some of the characters are sex -linked, (for
example the fleece characters of the Blackface x
Gritstone.) Of the other crosses that with the
Merino appears to be of the greatest interest, since
increased density of fleece could still be demonstrated
in the fourth generation of back- crossing to the
Blackface. In practically all crosses rams of other
breeds have been crossed with Blackface ewes.
Crossing with Border Leicesters and Wensleydale are
important commercial crosses, producing sheep, specially
useful for the butcher.
FACE COLOUR:
The relationship between face-colour and
various other factors has been considered, mainly
from data accumulated on the writer's own farm in
Perthshire during the past ten years. These results
indicate that breeders can, by selection of their
stock, with due regard to face colour, improve commercially
important points.
Sufficient data has been collected to show
that by selection of the parents for face colours, a
considerable proportion of the progeny will have those
colours which this work has shown to be desirable, i.e.
the extremes of face colour both black and white in
ewes have been shown to be associated with lambs of
inferior size and dead weights. That the face colour
of the sire is important because it is shown that
different colours are c-o,rrelat.ed with different decrees
of hardiness in his lambs. It has been demonstrated
that blackspotting in the fleece can be materially
improved by using sires free from this fault and that
black spotting and face colour are correlated.
FERTILITY.
It is shown that under a constant environment
bath high and low fertility is transmitted from
the sire to his daughters and is characteristically
exhibited by thee: subsequently. It has not however
been possible to test whether females may transmit
fertility factors to their sons, and only very limited
figures are given to show the influence of rams on
their grand - daughters and on their sons, since only
a few home -bred rams were used. Evidence is advanced
which suggests potential economic importance of the
influence of rams on the fertility of a Blackfaced
breeding stock; for although the average for barrenness
in this flock was 14%, one ram left daughters who were
never barren, another ram's daughters only had a figure
of 5% for barrenness, but four rams left daughters
whose barrenness figures were 22 %, 23%, 24% and 29 %.
FLOCK RECORDING:
It is very evident that much valuable information
on matters intimately concerned with breeding
and inheritance under practical conditions is lost
through the absence of a general system of marking and
flock recording. The experience of marking and recording
on which this work is based shows that the advantages
gained compensate for the expenditure of such time
and money as is involved
