36 



BULLETIN 1090, U. S. DEPARTMENT OF AGRICULTURE. 



Table 19. — The average birth weight in grams of young raised to 33 days. Control 

 stock by years, 1911 to 1920. 









[The 



average in each size of Utter and the index, as in Table 7.] 









Year. 



Size of litter. 



In- 

 dex. 



Year. 



Size of litter. 



In- 



1 



2 



3 



4 



5 



6 



1 



2 



3 



4 



5 



6 



dex. 



1911.. 



1912.. 

 1913.. 



99.5 



110.7 

 111.2 

 117.8 

 100.1 



93.6 



96.2 

 96.6 

 103.7 

 95.1 



80.2 

 88.5 

 83.0 

 85.5 

 84.5 



69.3 

 73.7 

 70.1 

 77.8 

 69.8 



65.1 

 67.9 

 64.2 

 72.7 

 64.5 



62.0 

 63.6 

 63.0 

 63.2 

 59.5 



84.0 

 90.1 

 87.3 

 92.7 

 86.3 



1916.. 

 1917.. 

 1918.. 

 1919.. 

 1920. . 



108.5 

 105.2 

 117.4 

 113.1 

 118.9 



88.7 

 86.8 

 91.3 

 97.9 

 95.9 



73.1 

 73.0 



73.8 

 80.9 

 83.4 



64.5 

 63.5 

 71.9 

 72.2 

 72.1 



53.7 

 64.5 



59.5 



79.6 



78.5 

 83.0 



1914.. 

 1915.. 



65.6 

 63.2 



60.1 

 51.2 



87.5 

 88.4 



Table 20. — The average gain between birth and 33 days, in grams. Control stock by 



years, 1911 to 1920. 



[The average in each size of litter and the index, as in Table 7.] 



Year. 



Size of litter. 



In- 

 dex. 



Year. 



Size of litter. 



In- 



1 



2 



3 



4 



5 



6 



1 



2 



3 



4 



5 



6 



dex. 



1911.. 



1912.. 

 1913.. 



195.0 



168.8 

 190.0 

 198.4 

 160.5 



141.5 



178.3 

 175.5 

 201.5 

 171.0 



136.7 

 164.4 

 135.9 

 167.9 

 131.1 



127.8 

 120.4 

 128.8 

 143.2 

 114.4 



92.6 

 139.7 

 109.3 

 114.0 



94.8 



120.0 

 112.9 

 103.4 

 130.8 

 95.0 



142.2 

 160.2 

 151.8 

 176.0 

 142.7 



1916.. 



1917.. 

 1918.. 

 1919.. 

 1920. . 



173.0 

 170.0 

 193.0 

 185.0 

 218.1 



137.2 



152.7 

 168.7 

 180.6 

 182.2 



102.0 

 129.8 

 135.0 

 147.8 

 161.3 



96.6 

 98.1 

 139.8 

 133.5 

 147.1 



102.5 

 90.7 



130.0 



118.6 

 134.3 

 151.9 



1914. . 

 1915.. 



112.8 

 123.7 



113.8 

 120.5 



158.5 

 170.4 



Table 21. — The average weight at 33 days, in grams. Control stock by years, 1911 to 1920. 

 [The average in each size of litter and the index, as in Table 7.] 



Year. 



Size of litter. 



In- 

 dex. 



Year. 



Size of litter. 



In- 



1 



2 



3 



4 



5 



6 



1 



2 



3 



4 



5 



6 



dex. 



1911.. 

 1912.. 

 1913.. 

 1914.. 

 1915.. 



294.5 

 279.5 

 301.2 

 316.2 

 260.6 



235.1 

 274.5 

 272.1 

 305.2 

 266.1 



216.9 

 252.9 

 218.9 

 253.4 

 215.6 



197.1 

 194.1 

 198.9 

 221.0 

 184.2 



157.7 



207.6 

 173.5 

 186.7 

 159.3 



182.0 

 176.5 

 166.4 

 194.0 

 154.5 



226.2 

 250.3 

 239.1 

 268.7 

 229.0 



1916.. 



1917.. 

 1918.. 

 1919.. 

 1920.. 



281.5 

 275.2 

 310.4 

 298.1 

 337.0 



225.9 

 239.5 

 260.0 



278.5 

 278.1 



175.1 



202.8 

 208.8 

 228.7 

 244.7 



161.1 



161.6 

 211.7 

 205.7 

 219.2 



156.2 

 155.2 



178.1" 



186.9 



189.5 



173." 9* 

 171.7 



198.2 

 212.8 

 234.9 

 246.0 

 258.9 



Table 22. — The number of males and females and the sex ratio {males per 100 females). 

 [Inbred and control stocks by years, 1906 to 1920.] 





Inbred stock. 



Control stock. 





Inbred stock. 



Control stock. 









S 







w 

 CD 







03 



CD 







CO 









03 







C3 









03 















a 







B 









a 







a 



Year. 







8 







<2 

 8 



u 



Year. 







<2 

 8 







8 





























CD 









& 





a> 



ft 







<D 



Pk 





■2 



ft 







1 



.2 



"c3 



£ 

 3 



03 



i 



3 





2 

 7a 



C3 



3 



"3 



8 



3 



c3 



.2 

 "3 





§ 



ft 



3 



§ 



ft 



3 





3 



fr 



3 



3 



ft 



3 



1906 



37 



35 



105.7 









1015 



1,129 



1,051 



107.4 



191 



211 



90.5 



1907 



343 



333 



103.0 









1916 



894 



879 



101.7 



223 



223 



100.0 



1908 



806 

 1,335 

 1,919 



855 

 1,223 



94.3 



109.2 









1917 



1918 . 



498 

 341 



480 

 329 



103.8 

 103.6 



209 

 151 



199 

 153 



105.0 



1909 









98.7 



1910 



1,922 



99.8 







1919 



556 



504 



110.3 



178 



187 



95.2 



1911 



1,188 



1,158 



102.6 



155 



143 



108.5 



1920 



704 



711 



99.0 



255 



209 



122.0 



1912 



1913 



1,135 

 1,051 



1,119 

 991 



101.4 

 106.0 



176 

 239 



160 

 199 



110.0 

 120.1 

















Total.... 



12,831 



12, 529 



102.4 



2,051 



2,007 



102.2 



1914 



895 



939 



95.3 



274 



323 



84.8 

















