Oxford Democrat. [volume] (Paris, Me.) 1833-1933, 1919-07-08
Gull Her Out In First Lactation.
SUGGESTIONS FOR GETTING RID OF THE
sLAcKER cow EARLY.

The culling OF so valuable an animal as
. COW ont of Q herd involves three ques-
tions. What has her production been In
previous lactations, what does 1t cost to
keep this cow for one year and third
what reliance can be placed In the first
lactation of Q heifer % measure of her
production In subsequent lactationsP
The first and second of these questions
are up to the dairymau to answer for
each and every COW In his herd through
the keeping of a cost record for each
COW and the returns from each cow
The third Of these questions requires Q
more extensive knowledge OF cattle
records than it is possible for most dairy.
men to accumulate.
The Maine Agricultural Experiment
Station In certain of it's cattle work has
studied q large number of records for the
first eight months of lactation to the end
OF answering this third question for pure
bred Jersey cattle. The following state
ments are for these pure bred jersey
cattle. While the figures given will not
be strictly true, the conclusions drawn
can undoubtedly be applied to other
breeds. In each of these records the
level of each cows record in the first
lactation was determined in relation to
the level In the total milk production for
the first five laotation periods. 1t was
found that the relative rate of milk pro-
duction remained very nearly the same
for the total milk produced by a COW in
her first five lactation periods as 1t did
In per first lactatiop. That is, If the
heller was high producer in her first
lactation she also was high producer
In the total production of her first five
lactations. If she was q medium pro-
ducer she was only q medium producer
In these lactations. If she was poor
producer in the first lactation she was
also poor producer in all five lacta-
tions. Relatively the COWS stayed very
close to the plane of production estab-
lished by their first lactation for the
total OF the other lactations.
These facts justify the dairyman who
is selling milk In culling the heifsrs
which lose money In their first year OF
lactation ont Of the herd for they will in
all probability be money losers for the
rest of their lives.
As an example of what this culling
will do for the average yield of milk in
herd of pure bred Jersey cattle the fol
lowing illustration may be given as taken
from these above mentioned studies.
The herd has had S8 cows which COM
pleted five lactations of eight months
each when they were under years old.
The COWS during this time were un-
affected by any disease so far as the
veterinarian could detect. The milk
records are consequently those of sound,
healthy cows. The average milk pro-
duction of these COWS as heifers was
400 pounds for the first eight months
of lactation. The question may be ask
ed, what was the production of the low
half and the high half of this herd for
the first five lactations? Or In other
words what would have been the gain in
average milk production by culling the
low producers from the berd9 The aver.
age yearly production of the low lot was
A. ,4S4 pounds, and of the high lot 5,556
pounds for the 6rst eight months of
each of the FIVE lactations. The annual
difference in average production of
these two groups for the first eight
months of each lactation was 1922
pounds. In fact on the average four
COWS in the high lot produced as much
milk as five COWS in the low lot. II
required one-fourth more food and one
fourth more labor to produce an equal
amount of milk from the low producing
half of the herd than from the high.
The preceding applies to quantity of
milk and not to pounds of butter-fat,
and is ntr'ctly applicable only to the
Jersey and iclated breeds. As milk pro-
duction and butter.fat production are
inherited differently the above might not
be the best guide to the man who is
selling butter-fat as such. But to the
seller of Jersey milk it is very clear that
cutting out the low producers in their
first year of lsctation pays good profit
and may make the difference between
success and failure. The yield of but
ter-fat in the first and subsequent lacta-
tlons will be discussed In another letter
In this series.-Chas. D. Woods, Director
Maine Experiment Station.