IMPROVING EGG PRODUCTION BY BREEDING. 22/ 



4. The use of a pedigree system, whereby it will be possi- 

 ble at least to tell what individual male bird was the sire of any 

 particular female. This amounts, in ordinary parlance, to a 

 pen pedigree system. Such a system is not difficult to operate. 

 Indeed, many poultrymen, especially fanciers, now make use of 

 pen pedigree records. It can be operated by the use of a toe- 

 punch. All the chickens hatched from a particular pen may be 

 given a distinctive mark by punching the web between the toes 

 in a definite way. If one desires to use a more complete indi- 

 vidual pedigree system, he will find the system described in 

 Bulletin 159 of the Maine Agricultural Experiment Station a 

 very simple and efficient one. It has been in use at this Station 

 for seven years, with entire satisfaction, on the score of both 

 accuracy and simplicity. 



5. The making at first of as many different matings as 

 possible. This means the use of as many different male birds 

 as possible, which will further imply small matings with only 

 comparatively few females to a single male. 



6. Continued, though not too narrow, inbreeding (or line 

 breeding) of those lines in which the trap-nest records show a 

 preponderant number of daughters to be high producers. One 

 should not discard all but the single best line, but should keep 

 a half dozen at least of the lines which throw the highest pro- 

 portions of high layers, breeding each line within itself. 



Items 4, 5, and 6 imply the carrying over of a considerable 

 number of cockerels until some judgment has been formed of 

 the worth of their lines, through the performance at the trap- 

 nest of their sisters. 



Item 6 assumes, as an absolutely necessary prerequisite that 

 item I will be faithfully and unfailingly observed. 



Some indication of the manner in which the application of 

 such a plan of breeding as that outlined will work out is given 

 in Figs. 74, 75 and 76. These figures show, in a diagrammatic 

 manner, the results of mating male birds of different hereditary 

 constitutions with respect to egg laying capacity, with females 

 which have been shown by the trap-nest to be high producers. 

 In these diagrams different geometrical patterns are used to 

 indicate, in the case of the female performing ability, and in 

 the case of the male the ability to transmit high laying quality 

 to his progeny. 



