The Democrat-sentinel. [volume] (Logan, Ohio) 1906-1935, 1907-06-20

the wrong principles or may ht
produced from stock that has
been bred according to wrong
idesls-ideals that are not con,
ductiye Ia the production Of the
best Kind ot Il market animal.
Where theee conditions exist is
true that Improvement may be
made by crose breeding but this
may also be done by good pure
breeding.
The adva antagee to he gained by
practicing pure preceding are as
follows: Suppose that a crop of
two hundred pigs are produced.
Only one nalf, or one hundred Of
them will be SOW pigs, from which
may he selected the gilte that are
to be put into the herd for future
service. Ont of the other
hundred pigs may he selected a
herd boar for future use.
According to one of the laws of
breeding, like produce like. Is
this true or untrue? Of all the
pigs ever seen by one individual, +,
or by all individuals combined,
were there ever two that looked
Just alike? The writer has never
seen such two pigs. 1t may, then,
be said that the above mentioned
law is not true. In detailed
way it is not, but in a general way
it is ANY species will always
reproduce its own kind.
Another law in breeding, name,
ly, the law of variation, brings in
to play it's influence, which is an
important one. There are always
variations from the average of
species. The greater numbe; Of
the offspring will lie nearer to
the general average Of the race,
some being better and others
poorer, and az one recedes from
the genelal average the nnmber
Of specimens gradually decreases,
and decreases more rapidly as the
distance from the general average
increases. Thus it is seen that
with large number Of specimens
it is possible to expect few very
good ones along with ii few very
poor once and larger number Of
average specimens
Suppose that a straight line
represents the average Of breed,
the upper side of The line represent,
ing those that are better ana the
lower side those that are poorer;
then the one hundred pigs of each
sex mentioned above on account of
the law of variation, will occupy
space on both sides of this line
in the form of circle. A con
siderable number Of pigs will be
somewhere near the axis of the
circle, representing the average of
the breed. A smaller number will
he little further above the axis,
while an equal number will be
equally distant below the axis.
A still smaller number will be
better than those occupying tie
upper part Of the circle, while
again an equal mum ber will oc.
cupy space equally distant on
the lower side of the line, represent
ing those that are not go good.
Thus as one recedas from the line
representing the average Of the
breed the number Of pigs decreasee,
those on the upper side of the line
being better and those on the
lower side being poorer.
In the practice of pure breeding
a breeder can 60 To his herd and
select those that appear in Il e
upper regions on the upper side
of this imse seinary line To nse for
breeding purposes, and by 30 do,
ing, instead Of staying on the
same plane, he is gradually but
surely improving his herd step by
step, by raising the line around
which his pigs will reyolye, which.
represents the general average
The larger the tcale upon winch
one operates the greater Ia his
opportunity for selecting good
individuals for breeding purposes,
and Tie greater viii he the i'm
prove ment year by year.
Ia cross breeding this npportun.
ity is entirely lost because the