Vernon County censor. [volume] (Viroqua, Wis.) 1865-1955, 1918-05-15

This is a question that perplexes
every dairy farmer. And here is the
answer-in plain, untechnical Ian
guage, from a source whose authority
| is recognized the country over.
Read it.
It will both interest and help you.
The question of variation in per
cent in cream marketed at different
creameries causes considerable trou-
BILE at times among their patrons and
will continue to do so until the farm
ers understand more fully the condi-
tions that cause this variation Most
farmers have learned that, by proper
adjustment of the cream screw, the
percent of fat in the cream may be
increased or decreased; but they have
noticed that their cream tests have
varied from to Is per cent or more
from week to week, or from season
| to season, even when the cream screw
has not been changed.
The farmer is apt to conclude that
when the milk is from the same herd,
and there are no apparent Irregular
ties in feeding. milking or separating
the cream, the per cent of fat in the
cream should not vary The extreme
him to feel that the cream is not being
accurately tested. The fact is, uni
form test from week to week would
be more indicative of dishonesty than
a variation of a few per cent in the
test. Occasionally an incorrect test
is made, but this is an exceptional
cause for variation rather than a
usual one.
1t is very true that great care is
needed to test cream accurately, and
there may be operators Of the Bah
cock test who are incompetent and IN
reliable, but such operators are rot
long tolerated by any creamery man
ager.
Factors affecting the per cent of
fat found in cream, other than posi-
BILE Inaccurate and dishonest testing,
may be summarized as follows:
Richness of milk separated.
Changes in temperature of milk.
Speed of separator bowl.
Rate of inflow to separator bowl.
Amount of skim milk or water used
in flushing the separator bowl
Any one of these five phases of
separator management will influence
the test of cream, even when the
cream screw has not been changed.
However, if a variation in these con-
ditions is avoided as much as possible,
the richness of the cream may be con-
trolled to a greet extent.
RICHNESS OF MILK SEPARATED
When the cream screw is set to de-
liver a certain per cent of fat in the
cream, under normal conditions there
will be a definite ratio between the
skim-milk and cream separated. That
is, if the separator delivers II pounds
of cream and 80 pounds of skim milk
from 100 pounds of3 per cent milk,
the test of the cream would be 25 per
cent. On the other hand, if 4 per
cent milk is separated under the same
conditions, instead of getting more
cream than from the 8 per cent milk,
we would get approximately the same
amount, viz, II pounds, but it would
test about SO per cent. The change
in per cent of fat in milk is caused
by several factors, one of which is
the change from dry feed to succulent
pasturage, which results in a decreas-
ed fat percentage. On the other hand,
in the fall and winter, when the cows
are advanced in lactation, and are put
on dry feed, fat percentage is increas-
ed.
The following table taken from Bull
letin No. $50, Indiana Agricultural
Experiment Station, shows results of
experiments in which the cream OBJ
tanned from milk containing different
percentages of fat varied from 20 to
80 per cent, though the milk was
run through the separator under the
same conditions, without changing
the cream screw:
Milk Cream Skim-rnilk
Per Cent Fat Per CT Fat Per CT Fat