Commercial Duck Farming--Incubation
The Pekin duck is essentially a non-broody breed. It, therefore, becomes
necessary to resort to incubators for the purpose of hatching the eggs.
Occasional ducks will sit if allowed to do so but it is not the practice
on commercial duck farms to allow them to sit and hatch their young. No
special means are taken to break them of broodiness other than not to
allow them eggs to sit on.
_Kinds of Incubators Used._ Both the smaller kerosene lamp heated
incubators and the large or mammoth hot water heated incubators are used
for hatching duck eggs. At the present time the mammoth hot water
machines are those which are in principal use due largely to the
lessened labor required to operate them.
_Incubator Cellar._ It is necessary to provide some room in which the
incubators can be installed and operated. This may take the form of a
cellar, or the incubators may be operated in rooms above the ground.
Many of the incubator cellars on duck farms are only partially under
ground and not a few of them are built entirely out of ground. The
particular size and shape of the cellar or incubator room will, of
course, depend upon the number of incubators to be installed and upon
their make and shape. Usually these buildings are constructed with
rather thick walls so that the temperature of the room will fluctuate
less with changes in outside temperature. Provision is also necessary by
means of windows or other ventilating devices to provide for good
ventilation in the room. The cellars are usually constructed with cement
floors as moisture is used freely and wooden floors would rot out
quickly.
_Incubator Capacity Required._ The aim on commercial duck farms is to
hatch all of the eggs produced which are suitable for the purpose.
Practically no eggs are sold except the cracked eggs or those which
would not give good results in the incubator such as too large or too
small eggs. Occasionally, of course, there will be sales of duck eggs in
comparatively large lots for incubation purposes where someone is
starting a duck farm. Occasionally also duck farmers buy from each other
a few eggs for incubation in order to secure new blood. On the whole,
however, practically all of the eggs laid are incubated and it is
necessary to have an incubator capacity sufficient to take care of the
eggs as they are produced during the flush season.
Since the egg production at this time will run around about 80% and
since the period of incubation is 28 days and a couple more days must be
allowed to take the ducklings out of the machines and to clean up the
machines, it is necessary to figure on 30 days between hatches. To take
care of the flush production at this time there would be required an
incubator capacity of from 20 to 25 eggs per head of breeding ducks. The
latter figure is a safer estimate than the former. Of course, eggs
sufficient to fill the entire incubator capacity are not put in the
machines at any one time but different lots are put in as soon as a
sufficient number is obtained to make it worth while. There will be,
therefore, eggs in various stages of incubation in different sections of
the machines at the same time. While Pekin duck eggs will run about 1/2
heavier in weight than hens' eggs they do not take up a proportionately
greater amount of space in the incubator. An incubator tray will
accommodate about 5/6 as many Pekin duck eggs as it will hens' eggs.
_Age of Hatching Eggs._ Duck eggs should be set as often as enough are
secured to fill one or more trays in the incubator or enough to produce
a sufficient number of ducklings to utilize brooding space to advantage.
Since duck eggs deteriorate more rapidly than hens' eggs they cannot be
kept so long before they are set. It is best not to save them for longer
than one week. During the season of flush production it is not, of
course, necessary to save them that long since enough eggs will be
secured to set each day if desired. The usual practice at this time is
to set twice a week. During the early part of the season when the
production of eggs is low and the temperature cool the eggs are often
saved for as long a period as two weeks without noticeably bad results.
_Care of Hatching Eggs._ Eggs for hatching should be kept in a cool
place. Any place suitable for keeping hens' eggs for hatching is a
suitable place for duck eggs. The temperature should be from 50 deg. to 70 deg.
Fahrenheit. Where the eggs are not kept longer than one week, it is not
necessary to turn them, especially if they are kept on end. If kept
longer than this it is safer to turn them once a day or once in two
days, handling them carefully so as not to crack any or to injure their
hatching qualities.
_Selecting the Eggs for Hatching._ Medium sized eggs are preferred for
this purpose. Therefore, the extremely large eggs and the very small
ones are thrown out. Rough shelled eggs or eggs with crooked or deformed
shells are likewise thrown out since they are not likely to hatch well.
Eggs that are badly soiled so that they cannot be tested easily are
washed but the clean eggs are not. All the eggs intended for incubation
purposes are sounded by striking them gently against one another in
order to detect and remove the cracked eggs. No selection is made on the
basis of color. The eggs may be white, creamy white or a blue, or bluish
green in color. At the present time a considerably less proportion of
the eggs show a blue tint than formerly. As the egg laying season
advances the eggs laid by the ducks tend to get a little larger.
_Temperature._ Up to the time of testing, that is, about the fifth day,
the incubator is run at a temperature of from 101 to 102 degrees. After
the fifth day the temperature is kept as near 103 as possible. The most
sensitive period for a duck egg is during the first 3 or 4 days of
incubation. If they are allowed to get too warm during this time the
germ may be killed while if the temperature is too low, development will
be retarded.
_Position of the Thermometer._ In figuring on the proper temperature at
which to run the incubator, the thermometer should be so placed that the
bulb is on a level with the top of the eggs, preferably touching a
fertile egg. If the thermometer bulb rests on an infertile egg the
temperature recorded will be lower than the actual temperature of
fertile eggs in the later stages of incubation, due to the animal heat
of the developing embryos, with the result that the machine would be
operated at too high a temperature.
_Testing._ It is common practice to make only one complete test. This is
done on the evening of the fifth day. Testing may be done by means of an
ordinary candling device such as is used with hens' eggs, each egg being
examined separately. To save time a piece of apparatus may be used which
is simple in construction and which simplifies the process of candling
considerably. This may be termed a testing table. It consists of a
table the same width as an incubator tray and longer than the tray. In
the table there is an opening the size of a row of eggs and beneath this
are placed several electric light bulbs with reflectors back of them so
as to throw the light up through the eggs. By sliding the tray along the
table each row of eggs is brought over the lights and their condition
can be quickly noted. At this test all the infertile eggs are taken out
as well as any eggs in which the germs have died. The infertile eggs
after a careful retest are then packed in cases and sent to market where
they are usually sold to bakers as tested eggs. While no second test is
made of the eggs left in the machines the experienced incubator operator
is constantly on the watch for and is constantly removing any eggs which
die at a later time. To the experienced eye the color of the egg
indicates that it has died as it takes on a sort of pinkish or darkish
tint. Duck eggs after they die will spoil very quickly and must be
removed promptly as the odor which they throw off is very strong and
will prove harmful to the other eggs. The inexperienced operator can
readily locate dead eggs by smelling over the tray.
[Illustration: FIG. 21. Interior of house for breeding ducks. Notice the
heavy bedding and the feeding track. (_Photograph from the Bureau of
Animal Industry, U. S. Department of Agriculture._)]
[Illustration: FIG. 22. Incubator cellar on large duck plant. Trays of
eggs set out to turn and cool. (_Photograph from the Bureau of Animal
Industry, U. S. Department of Agriculture._)]
_Turning the Eggs._ The eggs are neither turned, cooled nor otherwise
disturbed after they are put in the incubator until after they are
tested on the fifth day. From this time on they are turned twice a day,
morning and night, until they begin to pip.
_Cooling the Eggs._ There is a considerable difference in the practice
of incubator operators with regard to cooling. No cooling should be done
until after the first test. After this some incubator men cool the eggs
by dropping the doors of the machine. Others take the trays of eggs out
and put them on top of the machine. Cooling is usually done once a day.
The amount of cooling which the eggs require seems to vary greatly and
here again the judgment of the operator comes into play. About the best
general rule which can be given is that the eggs should be cooled until
they do not feel warm to the face but they should never be cooled to the
extent that they feel cold to the face or hands. The length of time to
bring this about varies with the age of the eggs and the temperature of
the room.
_Moisture._ A good deal of moisture is used in incubating duck eggs. It
is usual to begin to spray the eggs with water the next day after
testing. However, this may vary anywhere from the sixth to the tenth
day. They are sprayed quite thoroughly, some men using water enough so
that it runs out of the bottom of the machine. No particular care is
taken to see that the water used is warm. Ordinary water just as it
comes from the pipes is commonly used and is applied by means of a spray
nozzle attached to a hose. However, extremely cold water should not be
used for this purpose. This spraying is done once or twice a day as the
operator may think necessary until the eggs begin to hatch. In many
cases even then if the ducklings seem to be drying too fast after they
come out of the shell, or to be having difficulty to get out it is well
to open the machines and wet the eggs down thoroughly.
_Fertility._ The fertility varies with the season that is, with the
weather. At the beginning of the laying season when the weather is cold
the fertility usually runs rather low. This is likewise true at the end
of the laying season when the heat of summer sets in. During the
interval between these two times of low fertility there will usually be
one or more periods during which the fertility will go down and then
come back again. This seems to occur even though the weather remains
about the same and though there is no change in the method of feeding.
Fertility may be considered to be good when it runs about 85%. When the
fertility is running poor the hatching of the eggs left in the machines
after testing will usually be poor also.
_Hatching._ It takes longer as a rule from the time that the ducklings
pip the eggs until they hatch than it does with chicks. To retain the
moisture which is so necessary during hatching, the machines are usually
shut tightly and are not opened until the hatching is pretty well
completed unless it becomes necessary to add more moisture as indicated
above. The little ducklings should be left in the incubator until the
hatching is over and they are thoroughly dried off. As soon as the
hatching is completed, the ventilators in the machines are opened to
hasten the drying process. If the ducklings open their bills and pant
it is an indication that they are not getting enough ventilation and
this should be supplied by fastening the machine door open a little way.
If the ducks are not ready to be taken out of the machines by noon or
soon after, it is best to leave them until the next morning before
removing them to the brooder house. In the meantime, however, the old
eggs and shells and other refuse should be taken out. Usually the hatch
is completed in time so that the ducklings can be removed to the brooder
house on the afternoon of the 28th day. As a rule the earlier the hatch
is completed the better are the ducklings.
Figures secured on results in hatching for the entire season on Long
Island duck farms indicate that as a whole the duck raisers will not
average much over 40% hatch of all eggs set. Some hatches may run as
high as 60% or even more and in some seasons the average percentage will
run higher than 40. Some especially skilled operators may also secure
considerably better average results than this. It is quite a common
practice on the part of duck farmers to pay their incubator man a bonus
on all ducklings over 40% hatched during the season. This bonus may
range anywhere from $1 to $5 per thousand ducklings. Such an arrangement
serves to give the incubator man a greater incentive to give the
machines good attention and to secure just the best results of which he
is capable.
_Selling Baby Ducks._ Within the last two or three years there has
sprung into existence a small but increasing trade in baby ducks. They
are handled and shipped about the same as baby chicks. Baby ducks are
ready for shipment as soon as they are thoroughly dry, usually about 12
hours after the hatch starts to come off. They are neither fed nor
watered before shipment and are packed in cardboard boxes used in
shipping baby chicks. As a rule the shipping boxes will accommodate
about half the number of ducklings that they will chicks. Of course the
outside temperature very largely governs the matter of the number to a
compartment. In warm summer weather, a two compartment box intended for
50 chicks will accommodate 26 ducklings if well ventilated at the sides
and top. They are shipped by parcel post and can be sent anywhere within
a radius of one thousand miles if the trip does not require more than 36
hours. For best results the ducklings should not be allowed to go much
beyond this length of time before they are fed. On receipt they should
be placed immediately in a brooder already prepared for them.