The Effect of Pregnancy and Parturition on the Weight of Dairy Cows

Abstract

A study was made of the effect of pregnancy and parturition upon the weight cycle of dairy cows of the Ayrshire, Guernsey, Holstein, and Jersey breeds according to gestation periods from data accumulated from records for the period 1922 to 1934 of the dairy herd of the Dairy Husbandry Department of the University of Nebraska. The weights of the cows were obtained from three consecutive weighings made at the middle of each month and daily weighings beginning at the 265th day of pregnancy and continuing for 30 days after calving. A total of 656 separate gestation periods were tabulated according to the breed and the number of the gestation.