Broodiness 



In Rhode 



Though no different in appearance from 

 other Rhode Island Reds, this one can be 

 depended upon not to sit. 



BROODINESS in hens (sitting on 

 eggs for the purpose of hatching) 

 is of great economic concern to 

 poultry men because each broody 

 period means a loss of about 15 days 

 of egg laying. The instinct to sit is 

 almost universal in the American 

 breeds. This depressing effect on 

 egg production results in extra labor 

 and equipment to "break up"broody 

 hens. To discourage this tendency 

 to sit, hens are removed for three 

 or four days to slatted-floored coops. 

 Since the beginning of this cen- 

 tury, research has been directed to- 

 wards reducing the incidence of 

 broodiness in most flocks. In 1913 

 the breeding of Rhode Island Reds 

 for high egg production was begun 

 at this Station. The first genera- 

 tion of pullets laid an average of 

 114 eggs in the first year; 90 percent 

 of all the birds went broody one or 

 more times in that year. 



Breeding Procedure 



Complete families of pullets were 

 trapnested for a full laying year 



i( Research Professor, Poultry Husbandry 



without culling, that is, without dis- 

 carding inferior or defective birds. 

 (Trapnesting is an effective method 

 of obtaining an accurate egg record 

 of each bird.) Each generation was 

 produced by mating birds within 

 the line, but close inbreeding was 

 avoided. From 90 to 100 pedigreed 

 pullets were trapnested each year 

 for a complete record. This method 

 of breeding reduced the incidence of 

 broodiness to as low as one percent 

 but never completely eliminated the 

 instinct. 



Hormones Injected 



Since the hormone prolactin in- 

 creases in concentration during 

 broody periods and has been made 

 to induce broody behavior, all fe- 

 males in our nonbroody line were 

 tested by prolactin injections. It 

 was assumed that prolactin would 

 induce broody behavior in those fe- 

 males carrying the inherited ten- 

 dency for broodiness. 



Tests began in the summer of 

 1947. Hens usually reacted by not 

 laying for about 15 days. None of 

 the birds actually became broody, 

 and many did not react at all. 

 Those females showing little or no 

 reaction were used as breeders the 

 next year. 



Tests were repeated the following 

 summer, and breeders selected in 

 the same manner as in the previous 

 year. The complete absence of 

 broodiness in the last three genera- 

 tions is sufficient evidence that the 

 hormone test was satisfactory in 

 helping to eliminate completely the 



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