152 MASS. EXPERIMENT STATION BULLETIN 2+2 



Birds Used 



These studies cover a five-year period beginning with the flock hatched in 

 1922 and ending with the flock hatched in 1926. The birds are all pedigreed 

 Rhode Island Reds that have been pedigree-bred since 1913 with no outside 

 blood introduced since 1915. The greater proportion of the birds have been 

 bred for high fecundity, with only a limited number used for inbreeding, 

 broodiness and color studies. 



The method of management has not been changed during the period report- 

 ed. All chicks have been raised on a clean range under four-year rotation. 

 Quarantine measures have been regularly employed to exclude disease. Hatch- 

 ing dates have been kept constant froni year to year. There are eight hatches 

 each year at weekly intervals, beginning March 2.5 and ending May 1.5. About 

 250 day-old chicks are placed immediately on the range in each 10x12 brooder 

 house with coal heater. All live chicks are placed in brooder houses and no 

 culling is practiced. These chicks are driven outside each day beginning with 

 the fourth day. 



The character of the ration and the method of feeding were kept constant 

 throu,ghout the period rejjorted. Sexes are separated at about eight weeks 

 and the birds are given free range of a large grassy area with trees and 

 bushes for shade. In late summer green corn is cut and fed fresh daily. All 

 pullets are taken to the laying houses when about 150 days old and housed 

 according to hatching date in 30x30 open-front houses, 2.50 pullets per house. 

 Cockerels are taken to winter quarters at the same time. All culling is done 

 by families only. All physically normal sisters from desirable mothers are 

 retained, and no pullets are culled in the laying house at any time. 



Health Conditions 



As previously noted, strict precautions have been taken to avoid disease 

 epidemics and external and internal parasites. Clean ranges and scrupulously 

 cleaned and disinfected houses and utensils were used throughout the period. 

 The caretaker of young stock was Hot permitted to come in contact with adult 

 birds and the caretaker of adult birds did not visit the growing range. Rem- 

 edial measures were regularly employed to check all external parasites and 

 worm treatments were given to adult stock. Yards about the laying houses 

 are plowed up J'early and seeded to forage crops. Despite these precautions, 

 some disease epidemics have occurred. 



In September, 1922, chicken pox appeared in all young stock. It was a 

 mild outbreak and terminated after a few weeks without serious effects as 

 far as could be discerned. 



No disease epidemics appeared in the 1923 flock. The flock hatched in 1924 

 suffered heavy losses from roup which appeared early in March, 1925, and 

 caused nearly 60 per cent of the losses for the year. The flock of 1925 suf- 

 fered from an outbreak of pox which later developed into roup. First cases 

 of pox appeared about October 19, 192.5, and autogenous vaccine was admin- 

 istered to all birds February 19, 1926. Losses appeared to be greatly reduced 

 by the vaccine. The flock hatched in 1926 was afflicted with no recognized 

 disease outbreaks. All stock has tested free of Bacillary White Diarrhoea 

 throughout the period. 



