44 MANUAL OF DAIRY CATTLE BREEDING 



Ida of St. Lambert (twice) and Ida's Stoke Pogis (once). The 

 number of total possible ancestors is 16 or the inbreeding, Z 3 = 

 t% or 31.25 per cent. 



The student may calculate the inbreeding found in each of his 

 four pedigrees. Tabulate the inbreeding of the pedigrees for the 

 whole class, tabulating each group of pedigrees separately — Ad- 

 vanced Registry bulls, Advanced Registry cows, random sample 

 bulls, random sample cows. The protocol for this tabulation is 

 given on pages 46-49. Comparing the average per cent of inbreed- 

 ing for each group, what conclusion do you draw as to the influence 

 of inbreeding on the possibilities of an animal's having an Advanced 

 Registry record? Read Chapter VII in M . S. Sections relating 

 to inbreeding in: 



REFERENCES 



Pearl, R., Gowen, J. W., and Miner, J. R. 1919. Studies in Milk Secretion 

 VII. Transmitting qualities of Jersey sires for milk yield, butter-fat 

 percentage, and butter-fat, Maine Station Bulletin 281. 



Wright, Sewall. 1922. The effects of inbreeding and crossbreeding on guinea 

 pigs, U. S: Department of Agriculture, bulletins 1090 and 1121. 



King, Helen D. 1918, 1919, 1921. Studies in inbreeding, Jour. Exper. Zool., 

 vol. 26, pp. 1-98; vol. 27, pp. 1-37; vol. 29, pp. 134-175. 



Write a paper of 250 words giving a synopsis of the conclusions 

 you draw from your studies as to the influence of inbreeding. 



