Testing of Eggs During Incubation.

King Country Chronicle, Volume III, Issue 140, 18 March 1909, Page 3

Testing of Eggs During Incubation.

Many poultry keepers boast that they do not ever trouble to test the eggs when they once have set them, for when they are under hens they do not care about disturbing them, and when in machines they do not think-it matters. This is for want of reasonable forethought, because it is very disappointing to poultry keepers who have had a couple or more hens sitting for twenty-one days to find at the expiration of this time that not one-third of the eggs have produced chickens. Such a state of things means loss of valuable time, which is never again picked up, for if the eggs are tested and the clear ones taken away it is possible to put both lots of fertile eggs together under the one hen and give the other a fresh lot altogether. At the expiration of from six to eight days the egg should be examined and this is best done by candlelight, as the unfertile can be easily detected, and if the greater part be sterile, time is saved, and the stock birds can be put under closer observation and a new male bird introduced if necessary. A new laid egg. as should be wellknown to poultry keepers, appears clear and transparent when held between the eye and a candle, Unfertile eggs appear so still, even after being sat upon three weeks, but the eggs which contain embryo chickens then have a dark shadow in the centre, shading ofT to more transparency at the edges. The amount of srace will vary with ' time of incubation and size of eggs, j and perfect opacity will not be found I till nine or ten days have elapsed,even 1 with good sized eggs, but a ter a few ! experiments carried out by holding bel tween the thumb and forefinger and j turning the rest of the hand so as to ' t?hade the light as much as posisble, no mistake will be made, and even with the hand alone the condition of contents will be determined with certainty By using a plate of tin or zinc to shade the light, and holding the egg to an aperture in it cut to the shape, the light may be brought closer. There are excellent egg testers made by several manufacturers of incubators, and for the expenditure of from three to five shillings a capital appliance which will last for years can be obtained. With such an egg tester beiide the shadow in the centre, some of thermal I blood vessels can generally be distinguished, and after experience many breeders are able to pronounce upon the eggs by the fifth day, especially if a lamp k be used which has a lens to condense the light, such as a really good bicycle lamp, which answeres excellently. A hole may be cut in a book cover, or other sheet of thick card, and used in the name way. The sterile eggs up to eight or nine days are quite good enough for puddings, and if fresh when set, will be better than many bought eggs even for boiling; they may be used as food for chickens when egg food is given. Early in the season, when unfertile eggs are most likely to occur it is a good plan to set in every case two hens simultaneously. Then the fertile ones if many have to he rejected can all be given to one hen and the other set again. In any case if the majority are unfertile the waste of the sitting hen may be avoided by ascertaining the fact thus early.