RATE OF GROWTH IN RHODE ISLAND REDS 



By F. A. Hays, Research Professor of Poultry Husbandry, and 

 Ruby Sanborn, Research Assistant in Poultry Husbandry! 



Introduction 



Weight records are readily obtainable and probably furnish the most 

 universal measure of results in poultry experimentation. Extensive data on 

 rate of growth as measured by body weight are also of very great value to 

 breeders as standards to guide their operations. In recent years, through the 

 development of flocks with special reference to heavy egg production, there 

 has arisen an additional use of body weights of growing chickens as a pos- 

 sible criterion of sexual maturity, egg size, vigor and other essentials. 



In order to overcome the eflfects of varying environmental conditions such 

 as temperature, humidity, amount of sunshine, or available green food, it is 

 necessary to carry weight records over a series of years and on large num- 

 bers of individuals. Greater uniformity and consistency will be attained also 

 if the records are made on a single strain of the breed or variety being 

 studied. 



Character of Data Available 



The records used in this study cover the eleven-year period from 1918 

 to 1928, inclusive. The data were collected on the Massachusetts Agricultur- 

 al Experiment Station flock of Rhode Island Reds, bred since 1913 with 

 special reference to heavy egg production. This flock has been carried with- 

 out introducing outside stock since 1916. Close matings have been avoided, 

 but there is a considerable degree of relationship within the flock. 



Hatching dates have remained constant throughout the period. There were 

 eight hatches each year at weekly intervals beginning the nearest Sunday to 

 March 25. Chicks were taken from the incubators 36 hours after hatching 

 and placed in 10 by 12 brooder houses Mith coal stoves. As a rule from 200 

 to 250 chicks were placed in each house. All chicks were driven outside on 

 the ground for a short period on the fourth day and were given access to 

 outside runs with abundant grass at all times thereafter. No cod liver oil was 

 used in feeding chicks, and a four-year range rotation with abundant grass 

 was regularly employed. Chicks were not fasted before weighing at two 

 weeks of age. All later weights were taken after the birds had been fasted 

 for 12 hours. 



The records presented on egg weight, chick weight at hatching and weight 

 at two weeks were secured on stock used in hatchability studies and inbreed- 

 ing studies from 1923 to 1928. 



The four-week records cover the entire period from 1918 to 1928 on all 

 Rhode Island Reds in the flock. 



Records of weight at 16 weeks were obtained only in 1918 and 1921 and 

 include all Rhode Island Reds in the flock. 



^ Credit is also due Mr. Gordon Bcarse for assistance in compiling the records. 



