ON INHERITANCE IN THE PRODUCTION OF BUTTER FAT

H. L. RIETZ
1909 Biometrika  
1) Introduction. IT is the main object of this paper to present an investigation into inheritance in the production of butter fat. As far as I am aware, no statistical investigation has been published dealing with this question, notwithstanding its importance in a great industry and also its purely scientific interest. Production of hotter fat is one of the chief functions of the cow in the service of man. We are, in the present paper, concerned with the inheritance of this function, which is
more » ... unction, which is perhaps highly correlated with certain characters of the organism of the cow, but little or nothing is known of the quantitative value of such correlations. The source of the data is the Advanced Register of the Holstein-Friesian Association of America. The performance of an individual in the production of butter fat is not constant from day to day, but varies considerably. The records taken from the above register are in pounds of butter fat made in seven consecutive days, and are given along with the age of the cow at the time of the test. The tests for the register are all made, at present, under the supervision of representatives of State Agricultural Experiment Stations. In the earlier years of the register, certain private tests were accepted. Throughout our work, we have taken only records attested by authorized officials of the Association, who are, in general, representatives of State Agricultural Experiment Stations. In beginning this work over a year ago, there were available 17 volumes representing records of 17 successive years and Volume 18 has appeared for use in the latter part of the work. However, it turns out that Volumes 1-10 give very few pairs of variates that satisfy conditions which it seems desirable to impose. For this reason, only data from Volumes 11-18 are used. In the register, a cow often has a record when her dam has none, and in many more cases when her granddam has none. This is due in part to the fact that it is becoming more fashionable for breeders to enter their cows in the Advanced
doi:10.1093/biomet/7.1-2.106 fatcat:em6zynpx3vhkvbw6atssawizxi