ARTIFICIAL INCUBATION 



■with a hole in one side the shape of an egg. Hold a fresh egg 

 up to the light and it looks perfectly clear. When a fertile egg 

 has been incubated seven days, a dark spot surrounded by a 

 network of small veins can be seen. All eggs that still look 

 clear after the seven days' incubation, are infertile and should 

 be taken out. These infertile eggs can be used for cooking or 

 can be boiled and fed to the young chickens. On the tenth and 

 fourteenth days the eggs should be tested and the dead eggs 

 removed. 



The chickens will commence to hatch on the nineteenth and 

 twentieth days. After the hatch commences, do not open the 

 door of the incubator until the end of the twenty-first day. A 

 great many of the details of the management of an incubator 

 have to be learned by experience. FuU directions for operat- 

 ing accompany each incubator and should be carefully studied: 

 before the incubator is started up. There are quite a number 

 of good incubators on the market. Avoid buying an inferior- 

 machine because it is cheap. 



THE MORTALITY OF CHICKS 



AN INTERESTING INVESTIGATION INTO THE CAUSES OF DEATH IN INCUBATOR 

 CHICKS, AND THE MEASURES THAT WILL PREVENT SAME— MORTALITY GREATER 

 AMONG FEMALE CHICKS THAN AMONG MALE CHICKS— FAULTY INCUBATION 



JAMES R. COVERT 



E rapid growth of the poultry industry within 



recent years has been largely influenced by the 



perfection of the incubator. True, high priced 



meat has been a factor, but the setting hen 



has long since been distanced, and commercial 



poulterers could do little without the incubator. 



Just now the topic of greatest interest is 



"what incubator shall I buy? Which is best?" 



Singulraly, every one who has at any time run an incubator 



feels qualified to give advice. 



In buying an incubator, two things may be remembered 

 to advantage. No machine can hatch an infertile egg and no 

 machine is fool proof. In other words, our first consideration 

 should be fertihty and vitality in the egg; secondly, inteUigent 

 faithful manipulation of the incubator. These statements are 

 repeated in substance many thousands of times by incubator 

 manufacturers; they are hoary-headed truisms, but ever new to 

 the tyro. 



The feeUng that the "latest is the best" is conmion to many. 

 Without knowing why, these persons insist on having the very 

 latest and their satisfaction and sense of security when the 

 latest is finally purchased are so great that neglect of ordinary 

 and reasonable precautions often follow to the detriment of an 

 otherwise good hatch. 



While much greater perfection in the art of constructing 

 ingenious contrivances for incubation does not seem probable 

 for the future, the case is different with brooding. The great 

 mortality among incubator chickens is an engrossing subject. 

 In this connection the results of post-mortem examinations 

 into the cause of death of 826 incubator chickens, a study recent- 

 ly made in Rhode Island, are interesting and instructive. 



These studies were made for the purpose of ascertaining 

 with as much certainty as practicable the proportion of in- 

 cubated chickens which die, the causes of death, and what 

 measures are best adapted to check the losses. 



CHIEF CAUSES OF MORTALITY 



Of the 826 dead chickens examined, 387, or about 47 per 

 cent., were males, and 439, or 53 per cent, were females. Thus, 

 it would appear that the mortality among females chicks is 

 greater. 



The diseases discovered as a result of the post-mortem 

 examination range themselves under four different heads: (1) 

 hereditary or faulty inouiaation; (2) mechanical causes; (3) im- 

 perfect sanitation; (4) improperly balanced rations. 



First, to heredity and faulty incubation may be ascribed 

 the deaths that occur before extrusion and the abnormalities. 



Recent experiments Conducted in Germany demonstrate that 

 alternate periods of heat and cold occuring during incubation 

 influence very largely the proportion of cripples. Of the 826 

 dead chickens examined, 33 per cent, died as a result of heredi- 

 tary weaknesses or faulty incubation. The weakness exhibited 

 by these chicks resulted in a greater habihty to disease or in 

 abnormaUties. Fifty eggs selected from certain breeding pens 

 were incubated. Of the 50 eggs, 27 proved fertile, 19 chicks 

 hatched, and of these 19 only 12 remained aUve at the end of 

 ten days. Six of the dead chickens were tuberculous and all 

 of them had enlarged gall bladders. 



Not one of that lot reached maturity. The excessive mor- 

 tahty is attributed to congenital weakness, since chicks from 

 other parents did well under exactly similar conditions. 



EFFECTS OF INHERITED WEAKNESS 



Constitutional weakness may manifest itself in those cases 

 where the yolk is not absorbed at the normal rate. Just pre- 

 vious to pipping, the unassimilated remnant of the yolk of the 

 egg is drawn within the body cavity of the young chick. This 

 yolk sac is connected by a narrow tube with the intestine and 

 through this tube the Hquified yolk enters the intestine, there to 

 undergo digestion and absorption. This yolk within the body 

 cavity of the young chick provides it with proper pabulum until 

 the chick has gained sufficient strength to provide additional 

 nourishment through the mouth. While the young chick is 

 gradually acquiring strength, this unassimilated yolk within its 

 body is gradually disappearing as the chick is able to assim- 

 ilate larger and larger quantities of food by the mouth, until, 

 finally, at the end of perhaps a week, under natural condi- 

 tions, the yolk has practically disappeared — absorbed into the 

 alimentary canal and there assimilated as required. 



Now if this process of absorption is unreasonably delayed, 

 whether by reason of abndnnalities, congenital weakness, or an 

 over abundance of food through the mouth, the food provided 

 by nature as best suited to the chick fails of assimilation, weak- 

 ness results, the unabsorbed yolk decomposes, and the chick 

 is poisened — "bowel trouble," it is called. In a large propor- 

 tion of the chicks in this experiment which died just previous 

 to hatching, the yolk had not been drawn into the body cavity, 

 and 13.3 per cent, of the chickens which hatched, but subse- 

 quently died, showed trouble connected with the yolk sac. 



Mechanical causes, many of them clearly preventable, oc- 

 casion the death of many chicks. Means of prevention sug- 

 gest themselves to all who are familiar with the details of brood- 

 ing, and no extended discussion is deemed necessary. 



Imperfect sanitation, poor ventilation, and want of sun- 



49 



