News and citizen. [volume] (Morrisville, Vt. ;) 1881-current, 1893-08-31
work of the Agricultural Expert
ment Station
STATE AGRICULTURAL
EXPERIMENT STATION,
BURLINGTON, VT, 1898, !

Bulletin No. g. Newspaper Bulletin No. II.
ANNUAL RETORT OF THE DIRECTOR
PART II.
Variations In Quantity and Quality of Milk
A full record has been kept at the sta
ton of the milk of each COW year after
year, and many thousand analyses made.
The voluminOus records now on file fur
nish abundant data for determining the
changes that take place in the quantity
and quality of the milk of cow and
the influence that various circumstances
have on the quantity and quality.
A study of these records leads to the
following conclusions:
First-All cows shrink in quantity of milk as
they get further from calving. If they are far
row, this shrinkage in quantity is accompa-
MED by almost no change in quality, even IN
til they go dry, provided they still farrow.
If they are in calf, the milk increases in quail
ity as it decreases in quantity. This increase
Is slight-but One-twentieth during the first
blk months after calving-but becomes quite
pronounced just before the COW goes dry.
Second-Cows that calve in the spring aver
age giving more milk during the first three
months after calving than those that calve in
the fall. For the seventh, eighth and ninth
months this is reversed. Fall cows show
smaller variations in the quality of the milk
than cows that calve in the spring.
Third-The milk of a COW for the first few
days or weeks after calving is very variable in
quality. On the average it is thinnest just
after calving, becomes slightly richer during
the next two weeks and then holds almost
uniform in quality for the next four or five
months.
FOurth-Cows vary in the quality of their
milk from one milking to the next and from
day to day, the quality rising and falling with
out apparent cause. Such changes are usually
within per cent of fat though one COW was
known t. Cla.ree 2.GS per cent in two days.
The least oh .nGc of any of the cows in the sta
ton herd during an entire period of lactation
is O.33 per cent fat, the average change is 1.34
per cent, and the greatest change 2.7S per cent.
The largest variation in yield of butter is from
milk that required 20 pounds to make pound
of butter to quality of milk which would re-
quire but H. pounds. 1t is probably possible
that cases may occur of doubling of the rich
ness of the milk during different times in the
same period of lac alton.
Fifth-Just after calving the milk is poorer
in fat and in solids not fat than just before the
cow went dry. The average drop in fat is / ID
per cent, the greatest change being ass per
cent and the least O.49 per cent, The average
change in solids not fat is a fall of O.47 per
cent, with variations from decrease of 1.94
to an increase of 0.42 per cent.
SiXth-Most COWS give about the same quail
ity of milk year after year, beginning with this
quality at the first calving There is no gen.
eral tendency for the milk to become either
richer or poorer as the COW grows older.
Seventh-From one calving TO the next cows
may be expected to vary the general quality of
their milk not much more than a sixth of per
cent fat, and scarcely ever will show varia-
ton of more than a quarter of per cent.
Eighth-The milk of heifer tends TO agree
very closely in quality to that of her dam. The
average variation is a third of per cent of fat,
and the greatest difference is per cent-in the
case of an Ayrshire COW crossed with a Jersey
bull
Ninth-The present cheap, rapid and easy
methods of testing cows leave no excuse for
any dairyman's not knowing the quality of the
milk of each one of his cows. If two tests are
made, each of a mixed sample of four days
milk, one being taken six weeks after the COW
calves and the other six months after calving,
the average of these two tests will agree almost
exactly with the average quality of the milk
given during the entire milking period. There
will seldom be difference of as much as a
quarter of per cent of fat,
Tenth-If it is desired to know from tests
nearer together what quality of milk a COW
gives, very accurate results will be obtained by
making two tests 10 days apart, four months
after the COW calves, each test being on a
mixed sample of four days milk. The average
of these two tests with one-eighth of per cent
of fat added is surprisingly near the truth for
the average quality of the years milk.
Eleventh-In the long run, just about the
same results are obtained whether cows are
tested once a month or twice month.
Twelfth--Cows that have been properly fed
at the barn do not shrink in quality of milk
when turned to pasture. They usually increase
both in quality and quantity.
Thirteenth-Full feeding with grain at the
barn and while the cows are on pasture pro-
duces a much larger flow of milk during April
and May and causes the flow to keep up con-
later in the fall, No attempt was
made to ascertain whether this increase was
sufficient TO pay for the extra grain,
Fourteenth-The milk produced by the cows
of Vermont during the entire year contains on
the average All per cent of fat, and would if
rightly handled make pound of butter from
each y pounds of milk.
Fifteenth-The station herd was troubled
thorough disinfecting with sulphur and plen-
tiful use of laudanum. There is nothing to
prove conclusivelv that the treatment was the
cause of the cessation of the disease.
SiXteenth-The most noticeable effect of
abortion on the quality of the milk is to make
it richer than it would have been had the COW
gone full time. This quality, however, falls
during the first few months after abortion,
until by the third or fourth month it is of
about the same quality as would have been
given if the COW had calved naturally.
Seventeenth-The worst effect of abortion is
the decreased quantity of milk given. which
with the cows of the station amounts to about
a third of the full yield.
Record of the Station Herd For 1892.
Careful and very complete records of
the station herd were kept during the
year 1892 and showed that the IL regular
members of the herd averaged 7,197
pounds of milk, of such quality as to
make 351 pounds of butter each. The
records also showed that the herd con-
tanned on the average 81 cows, and that
these produced 7,02S pounds of milk
apiece and 384 pounds of butter.
The best Ayrshire gave 6,055 pounds
IF milk and 345 pounds of butter; the
best three Holsteins, $50 pounds of
milk and 388 pounds of butter; the best
,hree Jerseys, 7,130 pounds of milk and
I22 pounds of butter. The best record
If any COW in the herd within the year
was IL, 224 pounds of milk and SOC pounds
If butter.
Relative Value of a Cow For Cheesemak-
ing and Butter Making.
When the records of the various cows
n the station herd are compared as to |
he amount of butter and of cheese that |
,ould be made from their milk, it is
ound that if q pounds of cheese are
considered to be equal in market value |
o one pound of butter, then for every |
100 obtained from the Jersey milk
made into butter there would be re-
eived $95 if the milk had been made in |
o cheese. The relation with the Ayr |
hire milk is as 100 to 81, and with the |
1olstein as 100 to SO, the poorer milk |
icing little better adapted to cheese
making than the richer milk, but the
differences are not large. The important
act is brought out that they are all |
God for butter and all good for cheese,
nd that therefore the SO called "cheese
ow"-that is, the COW which is espe-
tally good for cheese rather than but
er-does not exist, and that whenever a
ow is found that is good for cheese
making purposes the milk of that COW
) equally good for the manufacture of
utter.
Aeration of Milk.
An extended series of tests with two
ifferent kinds of aerators and under
everal different sets of conditions leads
D the conclusions:
First-That the aeration of milk without
polling has no effect upon the Dreaming of that
nix, but if the milk is cooled during the AGRA
on the Dreaming of the milk will be less per.
,ct.
Secondary method of aerating milk that
oes not at the same time cool it does not make
le milk keep longer before it sours, but the
polling of the milk as soon as it is drawn from
he cow will retard the time of sourng.
he Effect of Weather Upon the Quantity
and Quality of Milk.
A second investigation of this matter
as made on the station herd during the
of 1892 The results of this