8 



CHICK BOOK 



The statements made in this bulletin are sensible and 

 conservative but leave one with a desire for more data and 

 more complete information. It states that: "We must 

 breed for constitutional vigor" because "the most important 

 problem before poultrymen is to maintain and increase the 

 constitutional vigor of the flock. This is because we are 

 asking more of the modern hen in proportion to her live 

 weight than we are expecting of any other class of domestic 

 animals.'' 



"A good hen is expected to lay in a year about five 

 times her weight in eggs. This means a reproductive process 

 on an average, at least every third day during the year, or 

 perhaps, in rare instances, every other day." 



We quote from Prof. Rice's Cornell bulletin the follow- 

 ing contributory causes to loss' of physical vigor, which the 

 bulletin cites, with some personal comment: 



"(1) Increased productiveness. Modern poultry hus- 

 bandry makes larger and larger demands on the strength of the 

 fowl. The wild jungle fowl, from which our domestic fowls 

 have come, is reported to lay less than one dozen eggs a 

 year. The modern fowl, under good care, is expected to 

 lay 125 to 150 or more eggs per year, and at the same time 

 to produce , eggs that will yield chickens having as strong 

 vitality as the parent. It must be evident that with any in- 

 crease in the average production, of a fowl there must be a 

 proportionate increase in the physical strength of the fowl 

 to enable her to thrive under the larger consumption of food 

 and heavier production of eggs." 



It may be (undoubtedly is) true that in some cases 

 prolific laying is a cause or a contributory cause of the loss 

 of constitutional vigor, but we are inclined to believe that 

 in many cases the danger from this source is overestimated. 

 We know of a good many poultry farms that have been in 

 successful operation for a dozen or fifteen years, where the 

 habit has been to breed from vigorous, well-matured pullets, 

 that were prolific egg producers, and were out of heavy 

 laying stock. On these same plants they continue to get, 

 year after year, strong, vigorous chicks that live and thrive. 

 There are other matters to be taken into consideration besides 

 the mere fact of heavy egg production. 



OJUprinij Jivm Late Selection-Weuh 



wV#f»^y 



Reproduced from Cornell Heading Course Bulletin No. 46. PuUeta in 

 group A averaged in weight over i pound more than those in group B. 

 All were hatched at the same time, in the same machine, leg-banded, and 

 brooded, fed and allowed to run together on free range duimg the sum- 

 juer. Observe the differences in type of body, size of comb, etc. 



Where fully-developed, well-grown healthy vigorous 

 fpxillets are used, there is little danger of lessening vitality 

 .during the first season. These same birds, if carried over to 

 i'be used as yearlings or two-year-olds — that is, a second or 

 •third breeding season — might, and probably would, show, 

 considerable loss of bodily vigor. Heavy layers are prone 

 to develop during the latter part of their first year of laying, 

 some weakness or degeneration of the egg laying organs. 



When this occurs, the bird ceases to be of value as a breeder' 

 and is useful only as an egg-laying machine until she reaches 

 the end of her scope. For this reason extreme care should 

 be exercised in the selection of yearlings and two-year-old 

 hens for breeding purposes. 



"(2) In-and-in-breeding without regard to vigor. 

 This practice is fre- 

 quent 1 y resorted 

 to in order to em- 

 phasize and de- 

 V e 1 o p high pro- 

 duction, or exhi- 

 bition or other 

 qualities. Close 

 breeding can be 

 followed with 

 success only when 

 the first consider- 

 ation is given to 

 mating strong in- 

 dividuals. Too 

 many times the 

 breeder has not 

 had the courage to 

 sacrifice a week 



Reproduced from Cornell Reading Course 

 Bulletin No. 45. Showing contrast in constitu- 

 tional vigor in Barred Plymouth Rock cockerels. 

 Strong specimen at left, weak at right. 



individual because of its other desirable qualities." 



There can be no doubt that in-and-in breeding, even 

 when great care is taken to select sound, vigorous specimens, 

 is always a menace to constitutional vigor. 



Breeding from Pullets 



"(3) The use of pullets instead of hens for breeding. 

 By breeding from pullets the breeder is undertaking to repro- 

 duce from fowls that have not yet reached maturity, and 

 that, presumably because of their well-known qualities of 

 heavy fall and winter laying, may have lowered their vitality 

 before the breeding season. It appears reasonable, therefore, 

 that the continued breeding, generation after generation, 

 from pullets instead of hens, may have a tendency to shorten 

 the normal length of life of the race of fowls, and, at the 

 same time, to lower its native vigor, while the breeding from 

 mature fowls, two or more years of age and still vigorous, 

 should tend toward longevity and a consequent increase in 

 vitality." 



We cannot wholly agree with the statements made in 

 the paragraph quoted above. Pullets are generally spoken 

 of as such until they have completed their first year of laying, 

 and in most varieties early hatched pullets are ready, and 

 safe to breed from in March and April at which time they 

 should be from eleven to twelve months old. It is never 

 safe to breed from undeveloped, immature pullets, but fully- 

 developed, well-matured specimens, well established in lay- 

 ing, make excellent breeders if carefully selected for health 

 and vigor. 



The practical profit-value age of the fowl is compara- 

 tively short, most practical plants preferring pullets and 

 yearlings, with.only a very limited number of two-year-olds, 

 the object being to get the greatest possible production dur- 

 ing the first two seasons of laying, and dispose of the bird 

 as market poultry before the muscles are sufficiently aged 

 and hardened to injure the sale of the fowl as prime market 

 poultry. The length of life of a fowl is not of the same im- 

 portance as with other farm animals. Under favorable con- 

 ditions fowls may live until from nine to twelve years old, 

 but they are seldom profitable after the third laying season'. 

 t 11 "^t^ Heavy feeding to induce large egg yield during 

 i&n and wmter, the unnatural season for egg production 

 Ihe trouble here arises from the attempt to do, at the same 

 time, twothmgs which are more or less antagonistic; namely, 

 to force a fowl to her highest digestive power by feeding her 

 rich, appetizing foods to increase production when prices are 

 high, and to expect her to produce eggs for hatching that 

 are normal in their supply of nourishment and fully imbued 

 with that mysterious something called life. Under normal 

 conditions in nature a fowl is allowed to devote the larger 

 part of the year to storing up energy in order to reproduce 

 in the nornial manner. A fowl to be used for breeding 

 siiould be selected far in advance of the breeding season 



