_ PART I. DUCKS
CHAPTER V. 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.
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. _