SELECTING BREEDING MALES FOR EGG PRODUCTION. 47 



1916 inclusive; in the 150 to 199 egg class in the years 1917 and 1918; and in the 

 200 to 249 egg class in the years 1920 and 1921. Hence in the preparation of 

 Chart II the birds hatched during the first five years have been grouped into one 

 polygon, those hatched in the next two years into a second polygon, and those 

 hatched in the last tAvo years into a third polygon. Low producers laid from to 

 99 eggs in their pullet year; medium producers laid from 100 to 199 eggs in their 

 pullet year, high producers laid over 200 eggs in their pullet year. 



Chart II shows that in the first five years there were 27.76 per cent low producers, 

 68.33 per cent medium producers and 3.91 per cent high producers. During the 

 two-year period following, the percentage of low producers fell to 8.75, the medium 

 class increased to 75.28 per cent, and the high producers increased to 15.97 per 

 cent. During the last two years, the low class fell to 1.67 per cent, the medium 

 class fell to 47.61 per cent, and the high class increased to 50.72 per cent. 



Table 1, presented below, gives the number of sires used, the number of dams 

 used, the number of pullets completing yearly records, and the average of all 

 annual records bj^ breeding years. The last column includes pullets hatched in 

 the respective mating years. 



Table 1. 



Referring to the first column of the table, it will be observed that during the 

 first four 3'ears of the experiment the average number of males was about 18, 

 while during the past five years the number was cut down to an average of about 

 13. This policy has given a greater opportunity to determine the breeding ability 

 of the sires and to regulate future mating with a greater degree of certainty, because 

 the breeding ability of the sires can be ascertained with a higher degree of accu- 

 racy when their progeny are trap-nested in large numbers. This fact made it 

 possible to regulate matings more carefully along specific blood lines. 



The number of dams used was greater during the first four years of the experi- 

 ment than during the last five. The range in number of dams for the nine-year 

 period is from 29 to 99. The use of fewer dams makes possible more rigid selection 

 standards and probably is of value in reducing variability in the flock. 



The average number of completed records per year is 243. In general, the mean 

 annual production of the flock shows progress from year to year. The first results 

 of breeding at the Station are shown opposite the mating year 1913. Seventy- 

 seven pullets averaged 146 eggs. These 77 pullets represent a selected group from 

 a larger number, and consequently show a higher average than the 120 pullets 

 hatched in 1914. The offspring of 1915 brings the average of the flock up to 123 

 eggs, and from that time to the present there has been uninterrupted progress, 

 except for the disease outbreak of 1920. The 121 pullets hatched in 1920 averaged 

 197 eggs. The 297 hatched in 1921 averaged approximately 198 eggs. There is 

 no noticeable tendency in the flock to produce a few phenomenal records, but 

 rather a general homogeneity in production. This tendency to uniformity is 

 probably traceable to the methods of mating for specific characteristics, and to a 

 certain degree of relationship mthin the flock. 



