Group Title: Bulletin - University of Florida Agricultural Extension Service ; 60
Title: Culling for egg production
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Permanent Link: http://ufdc.ufl.edu/UF00024086/00001
 Material Information
Title: Culling for egg production
Series Title: Bulletin
Physical Description: 15 p. : ill. ; 23 cm.
Language: English
Creator: Mehrhof, N. R ( Norman Ripley ), b. 1899
Publisher: Agricultural Extension Service, University of Florida
Place of Publication: Gainesville Fla
Publication Date: 1931
 Subjects
Subject: Poultry -- Florida   ( lcsh )
Poultry -- Judging   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references (p. 15).
Statement of Responsibility: by Norman R. Mehrhof.
General Note: "January, 1931".
Funding: Bulletin (University of Florida. Agricultural Extension Service) ;
 Record Information
Bibliographic ID: UF00024086
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 002570551
oclc - 47284517
notis - AMT6864

Full Text





HISTORIC NOTE


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
(EDIS)

site maintained by the Florida
Cooperative Extension Service.






Copyright 2005, Board of Trustees, University
of Florida







(Revision of Bulletin 47)


COOPERATIVE EXTENSION WORK IN
AGRICULTURE AND HOME ECONOMICS
(Acts of May 8 and June 30, 1914)


AGRICULTURAL EXTENSION SERVICE, UNIVERSITY OF FLORIDA
FLORIDA STATE COLLEGE FOR WOMEN,
AND UNITED STATES DEPARTMENT OF AGRICULTURE,
COOPERATING
WILMON NEWELL, Director




CULLING FOR EGG PRODUCTION

By NORMAN R. MEHRHOF


Fig. 1.-This hen laid 315 eggs in a
year. Note the type.


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


Bulletin 60


January, 1931







BOARD OF CONTROL


P. K. YONGE, Chairman, Pensacola
W. B. DAVIS, Perry
A. H. BLENDING, Tampa
FRANK J. WIDEMAN, West Palm Beach
RAYMER F. MAGUIRE, Orlando
J. T. DIAMOND, Secretary, Tallahassee

STAFF, AGRICULTURAL EXTENSION SERVICE

JOHN J. TIGERT, M.A., LL.D., President of the University
WILMON NEWELL, D.Sc., Director
A. P. SPENCER, M.S., Vice-Director and County Agent Leader
J. FRANCIS COOPER, M.S.A., Editor
R. M. FULGHUM, B.S.A., Assistant Editor
RUBY NEWHALL, Secretary

COOPERATIVE AGRICULTURAL DEMONSTRATION WORK
W. T. NETTLES, B.S., District Agent
H. G. CLAYTON, M.S.A., District Agent, Organization and Out-
look Specialist
J. LEE SMITH, District Agent
R. W. BLACKLOCK, A.B., Boys' Club Agent
HAMLIN L. BROWN, B.S., Dairyman
E. F. DEBUSK, B.S., Citrus Pathologist and Entomologist
N. R. MEHRHOF, M. AGR., Poultryman
WALTER J. SHEELY, B.S., Agent in Animal Husbandry'
J. E. TURLINGTON, Ph.D., Agricultural Economist"
FRANK W. BRUMLEY, M.S.A., Agricultural Economist, Farm
Management
W. R. BRIGGS, B.S.A., Assistant Agricultural Economist, Farm
Management
E. F. STANTON, Supervisor, Egg-Laying Contest

COOPERATIVE HOME DEMONSTRATION WORK
FLAVIA GLEASON, State Agent
VIRGINIA P. MOORE, Home Improvement Specialist
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

'In cooperation with U. S. D. A.
"Part-time.








CULLING FOR EGG PRODUCTION

By NORMAN R. MEHRHOF

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. Cull-
ing is the method employed in removing the undesirable birds from
the flock. Generally the term "culling" is confined to the prac-
tice of sorting hens during their laying period; nevertheless, suc-
cessful poultrymen are constantly using a system of culling, in-
cluding the selection of hatching eggs, the selection of the young
stock during the rearing period, the selection of pullets before
they are put into winter quarters, and the selection of the male
breeders.
MANAGEMENT OF THE FLOCK
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 and internal parasites. If
the flock is managed under the above conditions, assuming that
the flock is comparatively 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.

TRAPNESTING
Trapnesting individual birds is the most accurate method of
learning the egg production of an individual. It furnishes a daily
egg record of each bird.
Trapnesting is necessary for those breeders who desire to
pedigree or secure individual egg yields. It involves more equip-
ment and labor, and appears too unsuitable for the farm flock
operator or strictly commercial egg producer.

WHEN TO CULL
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






Florida Cooperative Extension


means the removal of all unthrifty and stunted birds. The pul-
lets that go into winter quarters should be selected according
to size, rate of maturity, and health. Those which are under-
sized, 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,
crooked beak, etc., should be eliminated.
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.

CULLING DEVICES
It is necessary in culling to handle and examine each bird. To
facilitate this, the birds should be shut up the night before. A













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

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.
Catching hooks made of stiff wire may be used to advantage






Culling for Egg Production


in picking up stray hens. Whatever method is employed, it is
most important to handle the flock without causing too much
excitement.
CULLING CHARACTERISTICS
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 together


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


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.
HEALTH AND VIGOR
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







Florida Cooperative Extension


activity. "A bird of high vitality should possess size, weight,
type, productive
Power, action."
(Quoted from
l "Judging Poultry
for Production,"
by Rice, Hall and
SB Marble.)


S
Fig. 4.-A poor producer, with a record of only 109
eggs in 357 days. Note sunken eye, shrunken
comb, and beefy head.


Fig. 5.-This hen produced only 81 eggs in 357 days.
Note head, shrunken eye, long beak, and shrunk-
en comb and wattles.


HEAD AND
ADJUNCTS

The general
appearance of
the head is a
good indication
of productive-
ness. The head of
the producer is
broad, flat on top
and fairly short,
with a well
curved beak. The
face is clean cut.
The poor pro-
ducer's head is
long, narrow,
crow shaped,
with a rounded
top, and has a
long beak. "The
head is the
source of nerv-
ous energy, intel-
ligence, tempera-
ment, expression,
disposition, loca-
tion of the
senses, and ac-
tions." The eyes
of a good pro-






Culling for Egg Production


ducer are full, round, prominent, and bright, setting well in
front of head near top of skull, while with the non-producer the
eyes are sunken and dull.
The comb and wattles of the producer are well developed and

















Fig. 6.-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.


Fig. 7.-These S. C. White Leghorns were high pen in the Fourth Florida
National Egg-Laying Contest. Note body conformation.






Florida Cooperative Extension


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.

BODY TYPE (CONFORMATION)

To secure heavy egg production it is important that the bird
have good body capacity for the consumption of large quanti-
ties of feed and for the manufacture of eggs. The heavy pro-
ducer has a long, broad back which extends well to the rear and
has depth from the back to the keel. This depth should extend
well to the rear also. The breast is full and deep.




























Fig. 8.-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
tapering.






Culling for Egg Production


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 pubic bones and the distance between the pubic bones and
keel is an indication of the quality of the bird. This spread will
vary with the laying condition of the bird. The greater the
spread or the deeper the abdomen, the better.

QUALITY

The quality of the bird is an important factor in determining
its condition. The abdomen of a heavy producer is soft and pli-
able, while that of a poor producer is hard and stiff. The skin
of 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 com-
pared to the fat, round
and coarse-scaled shanks
of the poor layer.
The quality of the pubic
bones should be noted
also. In the good produc-
ers these bones are thin
and flexible, while with
the poor producers they
are thick and non-flexible.
It should be remembered,
however, that the thick-
ness of these bones varies
considerably, depending
upon whether or not the Fig. 9.--Spread between pubic bones
and end of keel bones in good producer.
hen is in laying condition.
The vent of a high producer is large, open, moist, and
bleached, whereas with the non-producer the vent is small, dry,
puckered and yellow.

PIGMENTATION

The presence or absence of the yellow color in the bird's body
is a characteristic which assists the poultryman in learning






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about the productiveness of the individual. In all yellow-skinned
varieties before they start to lay the birds show yellow color in
the beak, eye-ring, ear-
lobes, skin and shanks.
This color comes from
the feed. If the flock of
poultry is fed on yellow
corn and plenty of green
feed, the yellow color
will be more pronounced
than in flocks fed white
corn and very little
green feed.
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 com-
mences to lay and manu-
Fig. 10.-Spread between pubic bones and facture egg yolks she ab-
end of keel bone in poor producer. The sorbs the yellow pigment
spread is only two fingers. 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 rap-
idly than the upper. It takes
about four to six weeks of lay-
ing for the beak to bleach. Fin-
ally, with continued laying the
yellow color leaves the shanks;
bleaching from the scales on
the front of the shanks first and
then from the scales on the rear.
It takes about four to six months
for the shanks to bleach out.
Fig. 11.-Spread between the pu- The rate of losing this yellow
bic bones of a poor producer--
only one-finger spread. color will vary with different


_







Culling for Egg Production


birds. Generally the thicker the skin the longer the time required
for complete fading. The larger birds usually bleach more slowly
than the smaller birds.
As soon as the hen stops laying the color returns in the same
order that it left; namely, vent, eye-ring, ear-lobe, beak, and
shanks. It returns more quickly than it leaves.
MOLT
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 oc-
curs in the summer and fall. Early molters are generally poor
producers and the late
molters just the oppo-
site. The early molter
loses much more time
than the late molter and
naturally is less profit-
able.
WING MOLT
Th e molting of the
primary wing feathers
is of interest in detect-
ing vacation periods.
The primary wing
feathers are separated '
from the secondary ".. '
feathers by an axial
feather. When a hen
stops laying she will usu-
ally drop the inner pri-
mary 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 Fig. 12.-Spread between the pubic bones
shed and so on until the of a good producer a three-finger
spread.
entire wing is molted. It
requires about six weeks to grow a new feather.
There are generally 10 primary feathers, although 9 or 11 are
sometimes found.
The poor producer drops one at a time and takes a long time






Florida Cooperative Extension


to complete the molt (24 weeks). The good producer may drop
and restore a few and start laying, keeping the old primary









A 6

Fig. 13.-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.

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.


Fig. 14.-Method of measuring depth of bird.







Culling for Egg Production


TEMPERAMENT
Heavy producers are gentle and do not object to being han-
dled. 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, squawky when caught, lazy, and listless.
They are the last to get off the roost and are not heavy eaters.

SUGGESTIONS ON JUDGING POULTRY
It is well to consider present production, persistence in laying,
and rate of production.


PRESENT PRODUCTION
In handling birds consider the vent, pubic bones,
ties, ear-lobes.


Producer
large
moist
dilated


Vent



Pubic Bones


comb, wat-


Non-Producer
small
puckered
hard


wide apart close together
Comb, Wattles, Ear-lobes
large small
glossy contracted
red dry, covered with white
scales
(The color of ear-lobes varies with breeds.)
PERSISTENCE IN LAYING
In examining birds for
persistence in laying con-
sider color (pigmentation),
molt. t 1


C
Producer
white (bleach-
ed out)


olor
Non-Producer
yellow


vent vent
eye ring eye ring
ear-lobe ear-lobe
beak beak
shanks shanks
Molt
late early
RATE OF PRODUCTION
The rate of production
can be determined by han-
dling the birds and observ-
ing these characteristics-


Fig. 15.-Type of heavy producing
bird. Note long, deep body, well
developed breast, and good head.







Florida Cooperative Extension


body capacity, abdomen, quality of skin, shanks, face, tem-
perament, and broodiness.


Body Capacity


Producer
large (depth, length and
breadth of body)
distance between pubic
bones large
distance between pubic
bones and keel bone
large
Al
full
soft
pliable
Qua
soft
thin
S
flat
fine scales
lean
clean cut
prominent eyes
Ter
friendly
active
alert
Br
non-broody


Fig. 16.-Type of good breeding
male. Note masculine head, in-
dicating plenty of vigor, and
long, deep body and well devel-
oped chest.


abdomen


Non-Producer
small
distance between pubic
bones small
distance between pubic
bones and keel bone
small

hard
compact


lity of Skin
hard
thick


hanks

Face


perament


oodiness


round
coarse scales

beefy
sunken eyes

shy
inactive
sluggish
broody


SELECTING PULLETS

L Pullets should be selected
before they are put into win-
ter laying quarters. These
pullets should possess good
health and good size. Pref-
erence should be given to the
early maturing bird. Also,
the birds should conform as
near as possible to the stan-
dard requirements for the
particular breed and variety
and should be free of dis-
qualifications.

SELECTING MALES
Vigor in the male bird is
most important. He should
be active and should con-







Culling for Egg Production


form to the standard requirements as to type, size, and color
markings. He should likewise be free of standard disqualifica-
tions. He should have a short, broad head, alert eye, long, broad
back and deep chest. Even if the male bird possesses attractive
pedigree, do not use him unless he has plenty of vigor and con-
forms to breed characteristics. Both pullets and cockerels
should possess constitutional vigor, size, sexual maturity, free-
dom from breed and variety defects.

GENERAL CULLING GUIDE
Good Producer Character Poor Producer
broad, short ................................... head ...... long, narrow, crow-shaped
bleached, short .................. .......... beak ..... long, yellow
bright, prominent ............................ eye ........dull, sunken
bleached .................. ................... eye-ring ...yellow
ear-lobe
lean, smooth ...................................... face ........coarse, wrinkled
large, bright .................................. comb ......small, shrunken, covered
with white scales
full, broad ................... .......... breast ......shallow, narrow
broad, long .......... ........................... back ......narrow, tapering
fine, pliable, expanded ................ abdomen ....small, coarse, thick
thin, velvety ....... ...................... ...... skin ........thick, coarse
thin, flexible, well-spread..........pubic bones.thick, hard, close together
bleached, lean, flat, fine scaled...... shanks ....fat, round, coarse scaled, yellow
late, rapid ........................................ molt .....early, slow
moist, large, bleached..................... vent ........dry, small, yellow

ACKNOWLEDGMENTS

A considerable amount of the information in this bulletin is based on
data contained in the following publications: Culling for Egg Production,
by H. L. Kempster, Missouri Extension Circular 188; Culling the Farm
Flock, by J. A. Davidson, Michigan Extension Bulletin 58; Culling for Egg
Production, by W. D. Buchanan, Washington (State) Extension Bulletin
149; How to Select Good Layers, by S. J. Marsden, Nebraska Extension
Circular 1416; Culling and Selecting for Egg Production, by G. O. Hall,
D. R. Marble, and J. E. Rice, Cornell Bulletin 175; Culling Poultry, by L. F.
Payne and H. H. Steup, Kansas State Circular 147; and Judging Poultry
for Production, by Rice, Hall, and Marble, published by John Wiley and
Sons.




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