Group Title: Bulletin - University of Florida Agricultural Extension Division ; 47
Title: Culling for egg production
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 Material Information
Title: Culling for egg production
Series Title: Bulletin
Physical Description: 12 p. : ill. ; 23 cm.
Language: English
Creator: Mehrhof, N. R ( Norman Ripley ), b. 1899
Publisher: Agricultural Extension Division, University of Florida
Place of Publication: Gainesville Fla
Publication Date: 1928
Subject: Poultry -- Florida   ( lcsh )
Poultry -- Judging   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
Statement of Responsibility: by Norman R. Mehrhof.
General Note: "June, 1928".
Funding: Bulletin (University of Florida. Agricultural Extension Division) ;
 Record Information
Bibliographic ID: UF00024085
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 002570270
oclc - 47284575
notis - AMT6579

Full Text


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source

site maintained by the Florida
Cooperative Extension Service.

Copyright 2005, Board of Trustees, University
of Florida

Bulletin 47

(Acts of May 8 and June 30, 1914)



^^a y.-"

Fig. 1.-This hen laid 315 eggs in a
year. Note the clean-cut head, promi-
nent eyes, long and deep body, bleach-
ed beak and shanks.

Bulletins will be sent free upon application to the Agricultural Extension
Division, Gainesville, Florida

June, 1928


P. K. YONGE, Chairman, Pensacola
W. B. DAVIS, Perry
E. W. LANE, Jacksonville
J. T. DIAMOND, Secretary, Tallahassee


J. M. FARR, A. M., PH.D., Acting President of the University
WILMON NEWELL, D.Sc., Director
A. P. SPENCER, M.S., Vice-Director and County Agent Leader
ERNEST G. MOORE, M.S., Assistant Editor
GRACE GREENE, Secretary to County Agent Leader

W. T. NETTLES, B.S., District Agent
H. G. CLAYTON, M.S.A., District Agent
J. LEE SMITH, District Agent
R. W. BLACKLOCK, A.B., Boys' Club Agent
HAMLIN L. BROWN, B.S., Dairy Specialist
E. F. DEBUSK, B.S., Citrus Pathologist and Entomologist
N. R. MEHRHOF, M. AGR., Poultryman

VIRGINIA P. MOORE, Assistant State Agent
LUCY BELLE SETTLE, B.S., District Agent
RUBY MCDAVID, District Agent
MARY E. KEOWN, M.S., District Agent
ISABELLE S. THURSBY, B.S., Food and Marketing Agent
MARY A. STENNIS, M.A., Home Dairy and Nutrition Agent


The object of culling hens is to increase the average egg pro-
duction of the flock and to retain for breeding purposes and for
egg production those hens which possess superior qualities.
Culling is the method employed in removing the undesirable
birds from the flock. Generally the term "culling" is confined to
the practice of sorting hens during their laying period; never-
theless, successful poultrymen are constantly using a system of
culling, including the selection of hatching eggs, the selection
of the young stock during the rearing period, the selection of pul-
lets before they are put into winter quarters, and the selection
of the male breeders.

It is necessary, if we are to cull successfully, that the flock be
properly managed. Good hens will appear as culls if they have
not received proper rations and good care. Pullets and hens
should be comfortably housed, fed a well-balanced ration, and
fed properly, if they are expected to produce eggs economically.
Sudden changes in feeding practices will affect production. Also,
birds should be free from external parasites. If the flock is man-
aged under the above conditions, assuming that the flock is com-
paratively free of disease, the poultryman is able to select the
producers from the non-producers, provided he becomes familiar
with the principles of culling as outlined.

Culling should be carried on at all times, beginning with the
selection of eggs that go into the incubator and following
through to the final disposition of the birds. With the growing
birds it means the removal of all unthrifty and stunted birds.
The pullets that go into winter quarters should be selected ac-
cording to size, rate of maturity, and health. Those which are
undersized, have poor health, and are slow in development should
be disposed of. The successful poultryman is studying his birds
at all times and gradually eliminating those which appear to be
unthrifty, have low vitality, or give indications of being poor
producers. Those which have deformities, such as crooked back,
should be eliminated.

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As a rule, culling of the laying flock is done during the sum-
mer months and early fall, from July to November, when great-
er accuracy is possible. It is a good practice to examine the flock
once a month, especially from early summer until fall. By cull-
ing at different times, the poultryman is able to reduce his pro-
duction costs with each culling.


It is necessary in culling to handle and examine each bird. To
facilitate this, the birds should be shut up the night before. A
great help in culling is to have a wire coop into which the birds
may be driven and from which they can be easily removed. A
convenient size would be a coop about five feet long, two feet
wide, and one and one-half feet high. The front end of the coop
is placed tightly against the opening in the house. The birds are
then driven in and the door closed and then they are removed
for examination through a door on top of the coop.

Fig. 2.-Type of hook for catching chickens.

Catching hooks made of stiff wire may be used to advantage
in picking up stray hens. Whatever method is employed, it is
most important to handle the flock without causing too much

There are a number of different characteristics which the
poultryman should consider carefully when culling his flock. In
fact, he should weigh all of the following characteristics to-

Culling for Egg Production

gether and decide whether the bird is desirable to keep over for
another year. It is not sufficient to consider just one or two of
these points.

Fig. 3.-Method of holding hen for examination.

Economical, efficient egg production is dependent upon good
health and constitutional vigor. Weak, undersized birds should
always be removed from the flock. Sometimes birds of the same
size show a variation in vigor. Vigor can be determined by look-
ing at the head parts of the bird and also by considering her
The general appearance of the head is a good indication of
productiveness. The head of the producer is broad and fairly
short, with a well curved beak. The face is clean cut. The poor
producer's head is long, narrow, crow-shaped, and has a long

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beak. The eyes in a good producer are full, round, prominent,
and bright, while with the non-producer the eyes are sunken
and dull.
The comb and wattles of the producer are well developed and
have a fine texture, whereas with the poor producer these parts
are undeveloped and coarse in texture. The condition of the
comb and wattles will indicate the condition of the bird. The
laying bird will have a comb that is bright red in color, full, and
velvety to the touch, while with the non-laying bird the comb
and wattles are pale, shrunken, and scaly.

Fig. 4.-Left: Head of high producer. Comb and wattles are full, bright,
and velvety; beak short, well curved; eye bright, prominent; beak, eye-
ring and ear-lobe pale in color. Right: Head of poor producer. Comb
and wattles are small, shrunken, scaly; eye dull, sunken; beak, eye-
ring, ear-lobes and shank have yellow color.

To secure heavy egg production it is important that the bird
have good body capacity for the consumption of large quantities
of feed and for the manufacture of eggs. The heavy producer
has a long, broad back which extends well to the rear and has
depth from the back to the keel. This depth should also extend
well to the rear. The breast is full and deep.
The bird that is a poor layer is narrow across the back and
tapers toward the rear, has a shorter keel and lacks depth in the
abdominal region. The breast is shallow and narrow. The spread
of the pelvic bones and the distance between the pelvic bones
and keel is an indication of the quality of the bird. This spread

Culling for Egg Production

will vary with the laying condition of the bird. The greater the
spread or the deeper the abdomen, the better.

The quality of the bird is an important factor in determining
its condition. The abdomen of a heavy producer is soft and pli-


Fig. 5.-Left: Back of good producer. Note the breadth, and how it ex-
tends to the rear. Right: Back of poor producer. It is narrow and

able, while that of a poor producer is hard and stiff. The skin
in the good producer is thin, fine and velvety, while with the
poor producer it is thick and coarse.
The shanks of the good producer are lean, flat and fine scaled
as compared to the fat, round and coarse scaled shanks of the
poor layer.
The quality of the pelvic bones should also be noted. In the

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Fig. 6.-Spread between pelvic bones
and end of keel bones in good producer.

Fig. 7.-Spread between pelvic bones and
end of keel bone in poor producer. The
spread is only two fingers.

good producers these
bones are thin and flex-
ible, while with the poor
producers they are thick
and non-flexible. It should
be remembered, however,
that the thickness of
these bones varies consid-
erably, depending upon
whether or not the hen is
in laying condition.
The vent of a high pro-
ducer is large, open, moist,
and bleached, whereas
with the non-producer the
vent is small, dry, puck-
ered and yellow.


The presence or ab-
sence of the yellow color
in the bird's body is a
characteristic which as-
sists the poultryman in
learning about the pro-
ductiveness of the indi-
vidual. In all yellow-
skinned varieties the
birds show before they
start to lay, yellow col-
or in the beak, skin and
shanks. This color comes
from the feed. If a
flock of poultry is fed
on yellow corn and plen-
ty of green feed, the yel-
low color will be more
pronounced than in
flocks fed white corn and
very little green feed.

Culling for Egg Production

In a non-laying pullet the yellow color is found in the vent, eye-
ring, ear-lobe (in white ear-lobed breeds), beak and shanks. As
the bird commences to lay and manufacture egg yolks she absorbs
the yellow pigment and it leaves the body first in the vent. With
continued laying it leaves the eye-ring, ear-lobe and then the beak.
The color leaves the base of the beak first and fading extends
from the base to the tip. The lower mandible bleaches out more
rapidly than the upper.
It takes about four to
six weeks of laying for
the beak to bleach. Fin-
ally, with continued lay-
ing the yellow color
leaves the shanks;
bleaching from the scales
on the front of the
shanks first and then
e- a" h s from the scales on the
rear. It takes about four
to six months for the
shanks to bleach out.
The rate of losing this
... yellow color will vary
wit h different birds.
Generally the thicker
the skin the longer the
time required for com-
plete fading. The larger
birds usually bleach
more slowly than the
smaller birds.
Fig. 8.--Spread between the pelvic bones As soon as the hen
of a good producer--a three-finger
spread. stops laying the color re-
turns in the same order
that it left; namely, vent, eye-ring, ear-lobe, beak, and shanks.
It returns more quickly than it leaves.

When a hen stops laying she usually goes into a molt. A par-
tial molt may occur at any season, but the body molt usually
occurs in the summer and fall. Early molters are generally poor

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producers and the late molters just
molter loses much more time than the
is less

Fig. 9.-Spread between the pelvic
bones of a poor producer-only
one-finger spread.

the opposite. The early
late molter and naturally

The molting of the primary
wing feathers is of interest in
detecting vacation periods. The
primary wing feathers are sepa-
rated from the secondary
feathers by an axial feather.
when a hen stops laying she will
usually drop the inner primary
feather next to the axial feather
first. If she remains in non-lay-
ing condition for two or more
weeks the second primary
feather will be shed and so on
until the entire wing is molted.
It requires about six weeks to
grow a new feather.

Fig. 10.-Method of measuring depth of bird.

Culling for Egg Production

There are generally 10 primary feathers, although 9 or 11
are sometimes found.

/ B
Fig. 11.-A shows the 10 primary wing feathers and axial feathers. B, nor-
mal wing molt, showing first three primaries in process of replace-
ment. Molt has been in process about six weeks. Shaded feathers are
old feathers.
The poor producer drops one at a time and takes a long time
to complete the molt (24 weeks). The good producer may drop
and restore a few and start laying, keeping the old primary
feathers another season. In some cases she may drop a number
at one time.
The early molter drops her primary feathers very slowly,
while the late molters may drop as many as four primaries at
a time.
Heavy producers are
gentle and do not object to
being handled. They are
the first off the roost in
the morning and the last
to return at night. They
are heavy eaters. The poor
layers are inclined to be
wild, squawking when
caught, lazy and listless.
They are the last to get
off the roost and are not
heavy eaters. i
Pullets should be select- Fig. 12.-Type of heavy producing
bird. Note long, deep body, well
ed before they are put into developed breast, and good head.

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winter laying quarters. These pullets should possess good health
and good size. Preference should be given to the early maturing
bird. Also, the birds should con-
form as near as possible to the
standard requirements for the
particular breed and variety and
should be free of disqualifica-


Vigor in the male bird is
most important. He should be
active and should conform to
the standard requirements as to
type, size, and color markings.
He should likewise be free of
standard disqualifications. He
S` should have a short, broad head,
Fig. 13.-Type of good breeding alert eye, long, broad back and
male. Note masculine head, indi- deep chest. Even if the male
casting plenty of vigor, and long,
deep body and well developed bird possesses an attractive
chest. pedigree, do not use him unless
he has plenty of vigor and conforms to breed characteristics.


Good Producer
broad, short
bleached, short
bright, prominent
lean, smooth
large, bright

Character Poor Producer


full, broad breast
broad, long back
fine, pliable, expanded abdomen
thin, velvety skin
thin, flexible, well-spread pelvic bones
bleached, lean, flat, fine scaled shanks
late, rapid molt
moist, large, bleached vent

long, narrow, crow-shaped
long, yellow
dull, sunken
coarse, wrinkled
small, shrunken, covered with
white scales
shallow, narrow
narrow, tapering
small, coarse, thick
thick, coarse
thick, hard, close together
fat, round, coarse scaled, yellow
early, slow
dry, small, yellow

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