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.