226 MAINE AGRICULTURAL EXPERIMENT STATION. I9I4. 



1. Selection of all breeding birds first on the basis of con- 

 stitutional vigor and vitality making the judgment of this so 

 far objective as possible. In particular the scales should be 

 called on to furnish evidence, (a) There ought to exist, for all 

 standard breeds of fowls, normal growth curves, from which 

 could be read off the standard weight which should be attained 

 by a sound, vigorous bird, not specially fed for fattening, at 

 each particular age, from hatching to the adult condition. These 

 curves we shall sometime have, (b) Let all deaths in shell, 

 and chick mortality, be charged against the dam, and only those 

 females used as breeders a second time which show a high 

 record of performance in respect to the vitality of their chicks, 

 whether in the &gg or out of it. This constitutes one of the 

 most valuable measures of constitutional vigor and vitality 

 which we have. If for no other reason than to measure this 

 breeding performance, a portion of the breeding females each 

 year should be pullets. In this way one can in time build up 

 an elite stock with reference to hatching quality of eggs and 

 viability of chicks, (c) Let no bird be used as a breeder which 

 is known ever to have been ill, to however slight a degree. In 

 order to know something about this, why not put an extra 

 leg-band on every bird, chick, or adult, when it shows the first 

 sign of indisposition? This then becomes a permanent brand, 

 which marks this individual as one which failed, to a greater 

 or less degree, to stand up under its environmental measures of 

 constitutional vigor. (d) Many of the bodily stigmata by 

 which the poultryman, during the last few years, has been 

 taught to recognize constitutional vigor, or its absence, have, 

 in my experience, little if any real significance. Longevity is 

 a real and valuable objective test of vigor and vitality, but it is 

 of only limited practical usefulness, because of the increasing 

 difficulty with advancing age of breeding successfully on any 

 large scale from old birds of the American and other heavy 

 types. 



2. The use as breeders of such females only as have shown 

 themselves by trap-nest records to be high producers, since it 

 is only from such females that there can be any hope of getting 

 males capable of transmitting high laying qualities. 



3. The use as breeders of such males only as are known to 

 be the sons of high producing dams, since only from such males 

 can we expect to get high producing daughters. 



