BKOODIXESS IN RELATION TO FK( INDITV IN THE 

 DOMESTIC FOWL 



Bv F. A. IIAVS and RUDY SANBORN 



XATrKK UK CiiAiiA(.Ti:u Bi;iMi Sti i)n;i) 



Broodiiics.s is tlic tendency of female birds tu incubate or atteni])t to incii- 

 liate eggs. Tlie broody hen stays on the nest, clucivs, rulHes featliers wl»en 

 disturbed, etc. It is a recurring cyclical trait in birds and should l)e consid- 

 ered as a normal phase of their reproductive process. It has no iiomologue 

 in mammals since they reproduce viviparously (developed young). In rep- 

 tiles, which are closely related to birds, we have oviparous reproduction, but 

 the eggs are hatched without the attention of the mother. 



.VU breeds of domestic chickens exhibit broodiness to some extent. The 

 Asiatic or meat breeds are ail intensely broody; tlie American l)reeds all 

 exhibit the trait to a considerable extent; and the Mediterranean lireeds, 

 although said to be non-broody, always give some broody females. 



There thus appear to be widely different degrees of broodiness. There have 

 iieen birds in the Massachusetts Station flock that first showed broodiness in 

 November of their pullet year and continued to exhilut its cyclical recurrence 

 to the extent of ten or twelve times during the first laying year. Contrasted 

 with tins is hen C 960 — non-broody during pullet year, twice broody the second 

 year, and non-broody the third year. Also hen C 1347 — non-broody as a 

 pullet, broody once for 23 days her second year, and non-broody her third 

 year. Hen C 476.3 was brood}' once as a pullet for 17 days and non-broody 

 her second year. On the other hand, we now have two hens (B C-ITC i.nd 

 B8797) that have completed four annual records without going broody. In 

 general, three measures of broodiness may be used: nan)ely, (1) the number 

 of broody periods per year, (2) mean length of each broody period, and (3) 

 total days of non-productiveness associated with broody periods. In all cases 

 the length of a broody period has been taken as the period between last egg 

 previous to going broody and first egg following "recovery." 



Effect of Metholl of Hcmdliufi 



With the domestic fowl efforts are made to check the manifestation of 

 Viroodiness so that the hen may begin laying again. Modern j)rai'ticc is to 

 coop such hens in slat-bottom coops, making nesting almost impossiiile. After 

 four to six days of such confinement, the bird may ordinarily be returned to 

 the flock without resuming nesting. Such hens .show wide diversity in length 

 of time before resuming laying. 



Trapne.sting and regular removal of all eggs from the nests seem to "dis- 

 ■ durage" the on.sct of broodiness. Punnett reports two cases of hens from ;. 

 liroody-frce race that were themselves non-broody for two years, later actually 

 incubating and hatching eggs. This particular phase of the prol)lem needs 

 further elucidation. 



Broodiness thus apjjcars to be a normal ]ihase of the re])rod!icfion of 

 domestic chickens. Its occurrence seems to depend upon environmental and 

 ])hysiological stimuli as will l)e pointed out later. 



