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BROODINESS IN RELATION TO FECUXUITY JN THE 

 DOMESTIC FOWL 



Bv F. A. HAYS and RUBY SANBORN 



Natuue of Chauacteii Being Studied 



Bloodiness is the tendency of female birds to incubate or attempt to incu- 

 bate eggs. The broody hen stays on the nest, clucks, ruffles feathers when 

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

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

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

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

 the eggs are hatched without the attention of the mother. 



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

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

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

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



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

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

 November of tlieir pullet year and continued to exhibit its cyclical recurrence 

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

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

 year, and non-brood\' tiie third year. Also hen C 13i7 — non-broody as a 

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

 3'ear. Ken C 476.5 was broody once as a pullet for 17 days and non-broody 

 lier second year. On the other hand, we now have two hens (BCl' > ; nd 

 B 8797) tiiat liave completed four annual records without going broody. In 

 general, three measures of broodiness may lie used: namely, (1) the nimilier 

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

 total days of non-productiveness associated witli liroody 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 Method of HandliiKj 



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

 broodiness so that the hen may begin laying again. Modern j)ractice is to 

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



Trapnesting and regular removal of all eggs from the nests seem to "dis- 

 courage" ihe onset of broodiness. Punnett reports two cases of hens from ;. 

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

 incubating and hatching eggs. This particular phase of the problem needs 

 further elucidation. 



Broodiness thus appears to be a normal pliase of the rejiroduction of 

 domestic chickens. Its occurrence seems to depend upon environmental and 

 physiological stimuli as will be pointed out later. 



