The name of the simple Bordeaux peasant is, and should be, permanently
associated with his discovery that the milking qualities of cows were, to a
considerable extent, indicated by certain external marks easily observed.
We had long known that capacious udders and large milk veins, combined with
good digestive capacity and a general preponderance of the alimentary over
the locomotive system, were indications that rarely misled in regard to the
ability of a cow to give much milk; but to judge of the amount of milk a
cow would yield, and the length of time she would hold out in her flow, two
or three years before she could be called a cow--this was Guenon's great
accomplishment, and the one for which he was awarded a gold medal by the
Agricultural Society of his native district. This was the first of many
honors with which he was rewarded, and it is much to say that no committee
of agriculturists who have ever investigated the merits of the system
have ever spoken disparagingly of it. Those who most closely study it,
especially following Guenon's original system, which has never been
essentially improved upon, are most positive in regard to its truth,
enthusiastic in regard to its value.
The fine, soft hair upon the hinder part of a cow's udder for the most part
turns upward. This upward-growing hair extends in most cases all over that
part of the udder visible between the hind legs, but is occasionally marked
by spots or mere lines, usually slender ovals, in which the hair grows
down. This tendency of the hair to grow upward is not confined to the udder
proper; but extends out upon the thighs and upward to the tail. The edges
of this space over which the hair turns up are usually distinctly marked,
and, as a rule, the larger the area of this space, which is called the
"mirror" or "escutcheon," the more milk the cow will give, and the longer
she will continue in milk.
[Illustration: ESCUTCHEON OF THE JERSEY BULL-CALF, GRAND MIRROR, 4,904.]
That portion of the escutcheon which covers the udder and extends out on
the inside of each thigh, has been designated as the udder or mammary
mirror; that which runs upward towards the setting on of the tail, the
rising or placental mirror. The mammary mirror is of the greater value,
yet the rising mirror is not to be disregarded. It is regarded of especial
moment that the mirror, taken as a whole, be symmetrical, and especially
that the mammary mirror be so; yet it often occurs that it is far
otherwise, its outline being often very fantastical--exhibiting deep
_bays_, so to speak, and islands of downward growing hair. There are also
certain "ovals," never very large, yet distinct, which do not detract from
the estimated value of an escutcheon; notably those occurring on the lobes
of the udder just above the hind teats. These are supposed to be points of
value, though for what reason it would be hard to tell, yet they do occur
upon some of the very best milch cows, and those whose mirrors correspond
most closely to their performances.
Mr. Guenon's discovery enables breeders to determine which of their calves
are most promising, and in purchasing young stock it affords indications
which rarely fail as to their comparative milk yield. These indications
occasionally prove utterly fallacious, and Mr. Guenon gives rules for
determining this class, which he calls "bastards," without waiting for them
to fail in their milk. The signs are, however, rarely so distinct that one
would be willing to sell a twenty-quart cow, whose yield confirmed the
prediction of her mirror at first calving, because of the possibility of
the going dry in two months, or so, as indicated by her bastardy marks.
It is an interesting fact that the mirrors of bulls (which are much like
those of cows, but less extensive in every direction) are reflected in
their daughters. This gives rise to the dangerous custom of breeding for
mirrors, rather than for milk. What the results may be after a few years it
is easy to see. The mirror, being valued for its own sake--that is, because
it sells the heifers--will be likely to lose its practical significance and
value as a _milk_ mirror.
We have a striking photograph of a young Jersey bull, the property of Mr.
John L. Hopkins, of Atlanta, Ga., and called "Grand Mirror." This we have
caused to be engraved and the mirror is clearly shown. A larger mirror is
rarely seen upon a bull. We hope in a future number to exhibit some cows'
mirrors of different forms and degrees of excellence.--_Rural New Yorker_.
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