UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATIONS
WILLARD M. FIFIELD, Director
Producing Hatching Eggs in
Means of Artificial Insemination
By J. CLYDE DRIGGERS
Fig. 1.-Males and females may be kept adjacent to each other in cages.
Single copies free to Florida residents upon request to
AGRICULTURAL EXPERIMENT STATION
BOARD OF CONTROL
J. Lee Ballard, Chairman, St. Petersburg
Hollis Rinehart, Miami
Fred H. Kent, Jacksonville
Wm. H. Dial, Orlando
Mrs. Alfred I. duPont, Jacksonville
George W. English, Jr., Ft. Lauderdale
W. Glenn Miller, Monticello
J. B. Culpepper, Secretary, Tallahassee
John S. Allen, Acting President
J. Wayne Reitz, Ph.D., Provost for Agr.-.
Willard M. Fifield, M.S., Director
J. R. Beckenbach, Ph.D., Asso. Director
R. W. Bledsoe, Ph.D., Assistant Director
Rogers L. Bartley, B.S., Admin. Mgr.3
Geo. R. Freeman, B.S., Farm Superintendent
W. H. Jones, Jr., M.Agr., Asst. Supt.
MAIN STATION, GAINESVILLE
H. G. Hamilton, Ph.D., Agr. Economist '
R. E. L. Greene, Ph.D., Agr. Economist :'
M. A. Brooker, Ph.D., Agr. Economist
Zach Savage, M.S.A., Economist
A. H. Spurlock, M.S.A., Agr. Economist
D. E. Alleger, M.S., Associate
D. L. Brooke, Ph.D., Associate
M. R. Godwin, Ph.D., Associate I
W. K. McPherson, M.S., Agr. Economist :
Eric Thor, M.S., Asso. Agr. Economist3
Cecil N, Smith, M.A., Asso. Agr. Economist
Levi A. Powell, Sr., M.S.A., Assistant
E. D. Smith, Ph.D., Asst. Agr. Economist
N. K. Roberts, M.A., Asst. Agr. Economist
Orlando, Florida (Cooperative USDA)
G. Norman Rose, B.S., Asso. Agr. Economist
J. C. Townsend, Jr., B.S.A., Agr. Statistician 2
J. B. Owens, B.S.A., Agr. Statistician '
F'. T. Galloway, M.S., Agr. Statistician
C. L. Crenshaw, M.S., Asst. Agr. Economist
B. W. Kelly, M.S., Asst. Agr. Economist
Frazier Rogers, M.S.A., Agr. Engineer 1 '
J. M. Myers, M.S.A., Asso. Agr. Engineer
J. S. Norton, M.S., Asst. Agr. Engineer
Fred H. Hull, Ph.D., Agronomist3
G. B. Killinger, Ph.D., Agronomist
H. C. Harris, Ph.D., Agronomist
W. A Carver, Ph.D., Agronomist
Fred A. Clark, M.S., Associate
E. S. Horner, Ph.D., Assistant
A. T. Wallace, Ph.D., Assistant
D. E. McCloud, Ph.D., Associate :'
G. C. Nutter, Ph.D., Asst. Agronomist
I. M. Wofford, Ph.D., Asst. Agronomist
E. 0. Burt, Ph.D., Asst. Agronomist
J. R. Edwardson, Ph.D., Asst. Agronomist :
ANIMAL HUSBANDRY AND NUTRITION
T. J. Cunha, Ph.D., Animal Husbandman 1 a
G. K. Davis, Ph.D., Animal Nutritionist
R. L. Shirley, Ph.D., Biochemist
A. M. Pearson, Ph.D., Asso. An. Husb."
John P. Feas:er, Ph.D., Asst. An. Nutri.
H. D. Wallace, Ph.D., Asso. An. Husb.3
M. Koger, Ph.D., An. Husbandman :
J. F. Hentges, Jr., Ph.D., Asst. An. Hush."
L. R. Arrington, Ph.D., Asst. An. Hush.
A. C. Warnick, Ph.D., Asst. Physiologist
E. L. Fouts, Ph.D., Dairy Technologist'
R. B. Becker, Ph.D., Dairy Husbandman
S. P. Marshall, Ph.D., Asso. Dairy Husb.8
W. A. Krienke, M.S., Asso. Dairy Tech.a
P. T. Dix Arnold, M.S.A., Asso. Dairy Husb.S
Leon Mull, Ph.D., Asso. Dairy Tech.-
H. H. Wilkowske, Ph.D., Asso. Dairy Tech.3
James M. Wing, Ph.D., Asst. Dairy Husb.
J. Francis Cooper, M.S.A., Editor '
Clyde Beale, A.B.J., Editor3
William G. Mitchell, A.B.J.,Assistant Editor
H. L. Moreland, Jr., B.S.A., Asst. Editor'
A. N. Tissot, Ph.D., Entomologist
L. C. Kuitert, Ph.D., Associate
H. E. Bratley, M.S.A., Assistant
F. A. Robinson, M.S., Asst. Apiculturist
R. E. Waites, Ph.D., Ass'r. Entomologist
S. H. Kerr, Ph.D., Asst. Entomologist
J. R. Christie, Ph.D., Nematologist
Ouida D. Abbott, Ph.D., Home Econ.'
R. B. French, Ph.D., Biochemist
G. H. Blackmon, M.S.A., Horticulturist"
R. A. Dennison, Ph.D., Hort. & Interim Head
F. S. Jamison, Ph.D., Horticulturist'
Albert P. Lorz, Ph.D., Horticulturist
R. K. Showalter, M.S., Asso. Hort.
R. H. Sharpe, M.S., Asso. Horticulturist
V. F. Nettles, Ph.D., Asso. Horticulturist
F. S. La'asse, Ph.D., Horticulturist 2
R. D. Dickey, M.S.A., Asso. Hort.
L. H. Halsey, M.S.A., Asst. Hort.
C. B. Hall, Ph.D., Asst. Horticu',urist
Austin Griffiths, Jr., B.S., Asst. Hort.
S. E. McFadden, Jr., Ph.D., Asst. Hort.
C. H. VanMiddelem, Ph.D., Asst. Biochemist
B. D. Thompson, M.S.A., Interim Asst. Hort.
M. W. Hoover, M.S.A., Asst. Hort.
Ida Keeling Cresap, Librarian
W. B. Tisdale, Ph.D., Plant Pathologist'
Phares Decker, Ph.D., Plant Pathologist
Erdman West, M.S., Botanist & Mycologist '
Robert W. Earhart, Ph.D., Plant Path.2
Howard N. Miller, Ph.D., Asso. Plant Path.
Lillian E. Arnold, M.S., Asso. Botanist
C. W. Anderson, Ph.D., Asst. Plant Path.
N. R. Mehrhof, M.Agr., Poultry Hush.1 3
J. C. Driggers, Ph.D., Asso. Poultry Husb.:
F. B. Smith, Ph.D., Microbiologist
Gaylord M. Volk, Ph.D., Soils Chemist
J. R. Ncller, Ph.D., Soils Chemist
Nathan Gammon, Jr., Ph.D., Soils Chemist
Ralph G. Leighty, B.S., Asst. Soil Surveyor
G. D. Thornton, Ph.D., Mi .rh;nl nii i t
C. F. Eno, Ph.D., Asst. .i : ,.i ,
H. W. Winsor, B.S.A., A. .., '. n..
R. E. Caldwell, M.S.A., Asst. Chemist '
V. W. Carlisle, M.S., Asst. Soil Surveyor
J. H. Walker, M.S.A., Asst. Soil Surveyor
William K. Robertson, Ph.D'., Ass. Chemist
0. E. Cruz, B.S.A., Asst. Soil Surveyor
W. G. Blue, Ph.D., Asst. Biochemist
J. G. A. Fiskel, Ph.D., Asst. Biochemist
L. C Hammond, Ph.D., Asst. Soil Physicist
H. L. Breland, Ph.D.. Asst. Soils Chem.
W. L. Pritchett, Ph.D., Soil Technologist
D. A. Sanders, D.V.M., Veterinarian
M. W. Emmel, D.V.M., Veterinarian :
C. F. Simpson, D'.V.M., Asso. Veterinarian
L. E. Swanson, D.V.M., Parasitologist
W. R. Dennis, D.V.M., Asst. Parasi.ologis
E. W Swaithout, D.V.M., Asso. Poultry
Pathologist (Dade City)
M. Ristic, D'.V.M., Associate Pathologist
J. G. Wadsworth, D.V.M., Asst. Poul. Path
NORTH FLORIDA STATION. QUINCY
W. C. Rhoades, M.S., Entomologis'y in Charge
R. R. Kincaid, Ph.D., Plant Patholovist
L. G. Thompson, Jr., Ph.D., Soils Chemist
W. H. Chapman, M.S.. Agronomist
Frank S. Baker. Jr., B.S., Asst. An. Hush.
T. E. Webb, M.S.A., Asst. Agronomist
Mobile Unit, Monticello
t. W. Wallace, B.S., Associate Agronomist
Mobile Unit, Marianna
I. W. Lipscomb, M.S., Associate Agronomist
Mobile Unit, Pensacola
I. L. Smith, M.S., Associae Agronomist
Mobile Unit, Chipley
.1. B. White. B.S.A.. Associate Agronomist
CITRUS STATION, LAKE ALFRED
A. F. Camp, Ph.D., Vice-Director in Charge
W. L. Thompson, B.S., Entomologist
R. F. Suit, Ph.D., Plant Pathologist
E. P. Ducharme, Ph.D'. Asso. Plant Path
J. W. Sites, Ph.D., Horticulturist
H. O. Sterling, B.S., Asst. Horticulturist
H. J. Reitz, Ph.D.. Horticulturist
Francine Fisher. M.S., Asst. Plant Path
1. W. Wander, Ph.D.. Soils Chemist
J. W. Kesterson. M.S.. Asso. Chemist
R. Hendrickson, B.S., Asst. Chemist
Ivan S'ewart, Ph.D., Asst. Biochemist
D. S. Prosser, Jr.,, 1., Asst. Engineer
H. W. Olsen, B.S., Biochemist
F. W. Wenzel, Jr., Ph.D., Chemist
Alvir, H. Rouse, M.S., Asso. Chemist
H. W. Ford,, Ph.D., Ast. Horticulturi
L. C. Knorr, Ph.D., Asso. Histolo-ist
R. M. Pratt, Ph.D., Asso. Ent.-Pathologist
W. A. Simanton, Ph.D., Entomologist
E. J. Deszyck, Ph.D., Asso. Horticulturist
C. D. Leonard, Ph.D., Asso. Horticulturi',
\V. T. Long. M.S., Asst. Horticulturist
M. H. Muma, Ph.D., Asso. Entomologist
F. J. Reynolds, Ph.D., Asso. Hort.
R. B. Johnson, Ph.D., Asst. Entomologist
W. F. Newhall, Ph.D., Asst. Biochemist
W. F. Grierson-Jackson. Ph.D., Asst. Chem.
Roger Patrick, Ph.D., Bacteriologist
M. F. Oherbacher, Ph.D.. Asst. Plant Physiol.
R. C. J. Koo, Ph.D., Asst. Biochemist
J. R. Kuylendatl. Ph D., Asst. Horticulturist
W. C. Price, Ph.D., Virologist
.1. J. McBride, Jr., Ph.D., Assistant Chemist
EVERGLADES STATION, BELLE GLADE
W. T. Forsee, Jr., Ph.D., Chemist in Charge
R. V. Allison, Ph.D.. Fitber Technologist
Thomas Bre er, Ph.D.. Physiolohist
J. W. Randolph. M.S., Agricultural Engr
R. W. Kidder, M.S., Asso. Animal Husb.
C. C. Seale, Associate Agronomist
N. C. Hayslip, B.S.A., Asso. Entomologist
E. A. Wolf, M.S., Asst. Horticulturist
W. H. Thames, M.S., Asst. Entomoloist
W. G. Genung, M.S., Asst. Entomologist
Robert J. Alien, Ph.D., Asst. Agronomist
V. E. Green, Ph.D., Asst. Agronomist
V. L. Guzman, Ph.D., Asst. Hort.
J. C. Stephens, B.S.. Drainage Engineer
A. E. Kretschmer, Jr., Ph.D., Asst. Soils
Charles T. Ozaki, Ph.D., Asst. Chemist
D. S. Harrison, M.S., Asst. Agri. Engr.
F. T. Boyd, Ph.D.. Asso. Agronomist
J. N. Simons, Ph.D., Asst. Virologist
D. W. Beardsley, M.S., Ass't. Animal Husb.
R. S. Ccx, Ph.D.. Asso. Plant Pathologist
Donald M. Coe, Ph.D., Asst. Plant Pathologis,
SUB-TROPICAL STATION, HOMESTEAD
Gee. D. Ruehle, Ph.D., Vice-Dir. in Charge
1. ',' Ph.D., Entomolo ist
I .. i ... ., Ph.D., Horticulturist
Robert A. Conover, Ph.D.. Plant Path.
John L. Malcolm, Ph.D., Asso. Soils Chemisi
R. W. Harkness, Ph.D., Ass',. Chemist
R. Bruce Ledin. Ph.D., Asst. Hort.
J. C. Noonan. M.S.. Asst. Hort.
M. H. Gallatin, B.S., Soil Conservationist
T. W. Young, Ph.D.. Asso. Horticulturist
WEST CENTER. FLA. STA., BROOKSVILLE
Marian W. Hazen, M.S.. Animal Husband-
man in Charge
RANGE CATTLE STATION. ONA
W. G. Kirk, Ph.D.. Vice-Director in Charge
K. M. Hodges, Ph.D., Agronomist
D. W. Jones, M.S.. Asst. Soil Technologist
F. M. Peacock, M.S., Asst. An. Husbandman
CENTRAL FLORIDA STATION. SANFORD
R. AV. Ruprecht, Ph.D.. Vice-Dir. in Charge
J. W. Wilson. ScD.. Entomologist
P. Westgate, Ph.D., Asso. Hort.
IBen F. Whicner, Jr., B.S.A.. Asst. Horl.
.1 F. Darby, Ph.D., Asst. Plant Path.
WEST FLORIDA STATION, JAY
C. E. Hutton, Ph.D.. Vice-Director in Charge
H. W. Lundy. B.S.A., Associate Agronomist
R. L. Jeffers, Ph.D., Asso. Agronomist
SUWANNEE VALLEY STA., LIVE OAK
G. E. Ritchey, M.S., Agronomist in Charge
GULF COAST STATION. BRADENTON
E. L. Spencer, Ph.D.. Soils Chemist in Charge
E, G. Kelsheimer, Ph.D., Entomologist
David G. A. Kelbert. Asso. Horticulturist
obitert 0. Magie, Ph.D., Plant Pa'thologist
J. M1. Walter, Ph.D.. Plant Pathologist
S. S. Woltz. Ph.D., Asst. Horticulturist
Donald S. Burgis. M.S.A.. Asst. Hort.
C. M. Geraldson, Ph.D., A
C. Sovcell, Jr., Ph.D., Asst. Plant Pathologis't
Watermelon, Grape, Pasture-Leesl.urg
.1. M. Crall. Ph.D., Plant Path. in Charge
C. C. Helms, Jr., B.S., Asst. Agronomist
I. H. Stover, Assistant in Horticulture
N\. N lrook., Ph.D., Plant Pathol,vi't
A. H. Eddins, Ph.D., Plan'i Path. in Charge
E. N. McCuhbin, Ph.D., Horticulturist
T. M. Dobrovsky, Ph.D., Asst. Entomologist
D. L. Myhre, Ph.D., Asst. Soils Chemist
A. M. Phillips, B.S., Asso. Entomologist'
John R. Large, M.S., Asso. Plant Path.
Warren O. Johnson. B.S., Meteorologist in
SHead of Department
In cooperation wi'ch U. S.
.* Cooperative, other divisions, U. of F.
i On leave
Fig. 2.-Doors for the cages should be of the swing-out type, hinged from
either side or bottom.
Producing Hatching Eggs in Cages by
Means of Artificial Insemination
By J. CLYDE DRIGGERS'
General ............. .. .. Dilution ... .. 15
Collecting the Semen .. .... 6 Time Involved in Operation ...... 15
Insemina'cion ... .... ... 11 Summary .. ... ..... 16
Distribution of the Semen ....... 14
Since the mid-thirties the practice of artificial insemination
has evolved from a scientific demonstration of little but aca-
demic interest to a practical and efficient method of producing
hatching eggs from chickens and turkeys.
Among other uses, the system now is considered an effi-
cient method of extending services of valuable males, particu-
larly older birds of proven quality that have been ineffective
in natural mating.
The rapid increase in the use of the cage-layer system for
producing eggs commercially and the success incident to this
particular type of poultry farming has caused the question
to be raised, "Can hatching eggs be produced in cages ?"
By combining the technique of artificial insemination with
good cage management, the answer is "yes". However several
considerations must be taken into account.
The first of these is the long-time effect in relation to knowl-
edge of inherited disease resistance of laying birds. There
is no answer to this problem at present, but it is reasonable
to expect that there would be no noticeable effects, particularly
for the first few generations. However, there is a possibility
of a loss of some disease resistance after many generations of
The second consideration is the nutrition of the breeding
birds. Nutritionists feel that they can prepare a satisfactory
The author wishes to recognize with appreciation the assistance ren-
dered by Mr. Carl F. Wright, Poultry Farm Supervisor, in preparing
a portion of the manuscript and in the conduct of the work reported.
Cages for this work were furnished by L. A. Pockman Company, Decatur,
Florida Agricultural Experiment Stations
diet for caged breeders. However, a constant search is under
way to improve the formulas now recommended. It might be
added that this problem was one of the primary reasons caged
layers were not successful when tried in Florida in the early
Then, there is the problem of mating the birds. Artificial
insemination can be applied in this type of operation with as
good results as could be obtained by natural mating, and it is
the purpose of this publication to bring out such possibilities.
Fewer male birds are required and just as high degree of fer-
tility should be expected through artificial insemination as by
natural mating. However, two persons are needed for artificial
insemination, this extra labor being the primary disadvantage
of this system of producing hatching eggs.
The possibilities of the production of hatching eggs under
the cage system are of interest especially to the broiler in-
dustry because of the low average egg production obtained from
broiler strains of hens kept on the floor.
If an 8 to 10 percent increase in production of hatching eggs
can be obtained from hens in cages over that from flocks kept
on the floor, then the production of hatching eggs in cages
could be economical, based on estimates of cost. As done
presently in cage-layer plants, this increase in eggs per year
COLLECTING THE SEMEN
Preparation and training of the male is of primary importance
in securing a constant supply of good quality semen.
After selection based upon the usual standards for breeding
sires, the male may be confined in a cage adjoining those
of the hens (Fig. 1). Cages 10 to 12 inches wide for light
breeds and 12 to 14 inches wide for heavy breeds are adequate.
Here he can be managed just as the hens, with no special
attention other than to check the wire spacing to insure ade-
quate size for free access to feed and water. It is well to place
him in the cage a day or two before training begins to permit
him to become accustomed to the environment. At this time
all feathers should be plucked from an area two to three inches
square around the vent to preclude interference with the collec-
tion process. This region should be kept free from feathers
as long as the male is used.
Producing Hatching Eggs by Artificial Insemination 7
The only equipment needed for securing the semen is the
container for its collection. A clean glass funnel having a
diameter of about 21/2 inches at the top and a stem approxi-
mately 21/2 inches long plugged with wax is recommended (Fig.
3). Such a container has the following advantages:
1. The stem provides a convenient handle.
2. The apex formed by the tapering sides makes possible
the complete utilization of the contents.
Fig. 3.-Equipment for securing the semen and making the insemination
is very simple. A funnel and graduated syringe or eyedropper are neces-
Because two operators are required to complete the in-
semination of females, it is advantageous to use the two-man
technique of securing semen from the male. First the bird
is removed from the cage, reasonable care being taken to pre-
vent undue excitement. He is then brought immediately into
position against the holder's body at approximately waist height.
He should be held by the thighs as comfortably as possible with
the legs in normal position under the body, the vent facing
outward. Care should be taken to avoid squeezing the legs;
in fact, the bird should be held rather loosely and as naturally
Florida Agricultural Experiment Stations
as practicable. Wings should be arranged in their normal
position against the body (Fig. 5).
Fig. 4.-Removing the birds from the cage head first is very satisfactory.
At this point the other operator begins the process of stimu-
lation necessary to bring about protrusion of the copulatory
organ from the cloaca and simultaneous ejaculation of the
Grasp the funnel in the right hand with the stem extending
downward between the last two fingers. Massage the bird
Producing Hatching Eggs by Artificial Insemination 9
a few seconds in the abdominal region with the receptacle held
ready to tilt forward and receive the fluid. The left hand
simultaneously strokes along the back in the direction of the
tail, increasing the pressure slightly as the tail region is ap-
proached. Frequently a slight tremor is felt throughout the
Fig. 5.-Holding the male in a relaxed position is important in securing
the maximum quantity of semen.
Florida Agricultural Experiment Stations
body of the bird just prior to the moment of ejaculation. With
the left hand the tail may now be pushed forward quickly and
the semen pressed from the distended rudimentary copulatory
organ by using the thumbs and forefingers of both hands in a
squeezing action at the sides of the vent (Fig. 6).
Fig. 6.-The two-man technique of securing semen from the male is
illustrated. Notice how the funnel is held to prevent loss.
It is important, particularly during the training period, that
the above operation be repeated until the available supply of
Producing Hatching Eggs by Artificial Insemination. 11
semen has been drained from the ducts. Such a procedure
is more likely to insure a satisfactory response in future opera-
The technique described is intended to be generally appli-
cable, but it should be understood that male chickens vary
widely in their reactions, both as among individuals and from
one time to another. Considerable variance may be noted also
in the amount and quality of semen produced. Approximately
1 cc (cubic centimeter) is a reasonable average, but the amount
varies from time to time and with different males. Good quality
semen is relatively thick, whitish, and free from blood or fecal
matter. In this connection it is a good practice during the
training period to perform the operation without the encum-
brance of the collecting receptacle; it is somewhat easier to
learn the technique, and fecal matter that frequently appears
during this period may be discharged without contaminating
the container. Instruments should always be cleaned and rinsed
thoroughly before being stored.
Apparently, the optimum frequency for the collection of
semen from a particular male is once a day. Collection at
shorter intervals is possible but probably results in a reduced
total contribution over a long period. On the other hand, no
advantage is evident when the intervals are extended to two
days or more. In fact, a decline in total product may ensue.
However, a short rest of two or three days may be of value
as a corrective measure in the event that blood appears in the
An instrument for transferring semen from the receptacle
into the oviduct of the female is all the equipment needed for
insemination. A tuberculin syringe consisting of a thin glass
cylinder enclosing a plunger is reasonably convenient. Such
an instrument having a capacity of 1 cc and calibrated in
graduations of 0.01 cc provides accurate measurement (Fig. 3).
A simple medicinal eyedropper is satisfactory but somewhat
less accurate unless marked off for measurement. If a funnel
is used as the collecting receptacle, a small empty jar is useful
as a stand for holding the container upright.
No special preparation of the females is required except that
they be in production. It is suggested that feeds of special
appeal, such as scratch grains or pellets, not be distributed im-
mediately prior to handling the birds. There is the possibility
Florida Agricultural Experiment Stations
of excessive regurgitation which can be extremely irritating
to the operators, particularly when large numbers of birds
Fig. 7.-Complete protrusion of the oviduct is important for
The manner in which the female chicken is removed from
the cage is important, particularly from the standpoint of the
time involved in completing the operation. She should never
be handled roughly nor dragged from the cage. The design of
Producing Hatching Eggs by Artificial Insemination 13
the cage door is a significant factor in rapid removal and re-
placement of the bird and will be discussed later in more detail.
Generally it saves time to turn the chicken around if neces-
sary so that she faces the front before removal (Fig. 4). Then
she may be lifted from the cage by the operator, using the
right hand in support under the body and the left hand above
to maintain balance and suppress fluttering. The operator now
has the chicken in a favorable position to be prepared for actual
Fig. 8.-The semen is not released into the oviduct until after this organ
has been withdrawn into the cloaca.
Florida Agricultural Experiment Stations
It has been found that a much higher degree of fertility
is obtained if all of the spermatozoa are introduced directly into
the oviduct, rather than to permit some to be dissipated in the
cloaca. For this reason it becomes necessary for the operator
to effect an extrusion of the oviduct in such a manner that it
will be accessible for the introduction of the syringe.
Such a protrusion is frequently accomplished spontaneously
by the chicken if her tail is suddenly pushed forward over her
back; in practice, however, the operator brings it about by the
appropriate application of pressure. With the palm of the right
hand supporting the bird and the three middle fingers stretch-
ing backward and upward toward the tail, the skin beneath
the vent may be pulled taut. Simultaneously, the thumb and
forefinger of the left hand perform a similar function in the
region above the vent as the tail is forced forward. The bird
is now compressed between the hands with sufficient pressure
to effect the protrusion desired (Fig. 7). At this point a second
operator inserts the tip of the syringe containing the fluid about
one inch into the oviduct. However, the syringe is not dis-
charged immediately-this is an important point. In order to
insure the introduction of the spermatozoa well inside the ovi-
duct, release of the semen is delayed until the pressure on the
bird has been relaxed, the tail returned to its normal posi-
tion, and the oviduct withdrawn into the cloaca (Fig. 8). The
instrument is then discharged and removed from the vent. Some
females, particularly the heavier ones, have a loose fold of
tissue in the cloaca which lies over the opening of the oviduct,
unless the protrusion is quite complete. Further protrusion
will result in complete exposure which should be accomplished
for best results.
DISTRIBUTION OF THE SEMEN
Though female chickens differ in amount and frequency re-
quired for the maintenance of a high level of fertility, an injec-
tion of 0.10 cc of semen once a week has been found to be a
satisfactory average. Experiments indicate that, for most
birds, dosages in excess of the above are unnecessary and, in
fact, wasteful. On the other hand, dosages smaller than 0.05
cc are not recommended, because of the ensuing reduction in
fertility in some females and the difficulty of accurate measure-
ment. Reduced quantities may be justified, however, when a
sample from a particular male is considered to be of exceptional
Producing Hatching Eggs by Artificial Insemination 15
quality and it is desired to apportion it among a large number
of females; a decrease in the level of fertility is likely, but it is
improbable that this decline will be in proportion to the reduction
On the basis of the average quantity of semen collected
per male (1 cc daily) and the dosage suggested per female
(0.10 cc once a week) it is possible to calculate the approximate
number of hens that may be serviced per male. One male
chicken provides a quantity of semen sufficient to inseminate
8 to 10 females a day. Assuming a five-day working week
for the operators, it can be seen that one male is required for
40 to 50 hens. Research based on the foregoing figures indi-
cates that a fertility of approximately 90 percent may be
expected with fresh, undiluted semen.
The operator engaged in the type of operation under discus-
sion has one major objective-to produce as many high quality
hatching eggs as possible using the least number of males.
Results of several attempts to augment the supply of semen
by dilution without a corresponding loss of fertility were dis-
appointing. Tests were made using egg whites and egg yolks
as diluents, each combined with fresh semen in a ratio of 9
parts diluent to 1 part semen. Neither mixture produced a level
of fertility in excess of 35 percent, though the addition of yolk
appeared to reduce fertility somewhat less than did the white.
Diluted semen, injected after 36 hours storage at 55 degrees
Fahrenheit was unproductive-in fact, fertility was virtually
non-existent. Consequently, dilution on the basis of the research
cited above clearly is not justified. It is possible, however,
and may be expedient to raise the total level of fertility slightly
by mixing the fresh, undiluted semen from two or more males.
TIME INVOLVED IN OPERATION
Females can be handled at the rate of from two to three
a minute from cages designed for easy removal and replace-
ment of the birds. The collection operation is somewhat slower
than insemination, due to the necessity of repeating the process
in order to exhaust the available supply and obtain the maxi-
mum product. It has been suggested that time may be saved
by turning the birds to face the front of the cages before
Florida Agricultural Experiment Stations
removal. In this respect cages 12 inches wide are distinctly
preferable to the narrower types, particularly for the dual-
purpose or heavier breeds.
Cage door design and size of openings are significant factors
the efficient and rapid handling of the birds. In experimental
work, doors of the vertical sliding type were found to be satis-
factory with respect to ease and simplicity of operation, but
considerable difficulty was encountered in removing the birds
through the six-inch apertures with which these particular
cages were equipped. However, these cages are commercial type
laying sections and are not designed for use in a type of opera-
tion where the chickens must be removed frequently. Cages
with swing-out doors are highly preferable for this type of
operation. A time saving of 25 percent is estimated with
10-inch openings, as compared to the six-inch width. Cages
having narrow openings and doors may be easily altered to
facilitate rapid handling of the chickens. A door made of the
same material as the cage (1 x 2-inch wire fabric) is illustrated
(Fig. 2). Hinged at the bottom to open outward, it is secured
at the top by a common spring clothespin. Swing-out doors
hinged along the side or at the top can be substituted in some
Fertile eggs for hatching purposes can be successfully pro-
duced in cages by artificial insemination.
Up to 90 percent fertility may be obtained, particularly if
samples of semen from two or more males are combined.
The technique can be learned easily and with a little practice
two trained operators can process an average of from two to
three birds per minute.
Equipment needed is simple and relatively inexpensive.
No special quarters are required to house the males other
than those provided for the females.
When cages are to be used for the production of hatching
eggs, swing-out doors should be provided so that maximum
advantage of width in removing the birds can be had.