Studies of Herd Management Records II. Relation of Gestation Length to Birth Weight of Holstein Calves of both Sexes at Various Calvings

Abstract

A study of 755 normal gestations, 384 male births and 371 female, of Holstein calves in the University of Nebraska herd during the period 1897-1950 was made to determine the relationship between length of gestation and birth weights of calves, by sexes and successive calvings. Gestation length for each sex and for the successive calvings showed no significant trend. The average gestation length for males was 278.9 days and for females 278.4 days. The average birth weight for males was 96.7 lb., and for females 90.3 lb. Analysis of variance showed that differences in birth weight due to sex, calving sequence, and gestation length were significant (P < 0.01). Correlation between gestation length and birth weight was 0.26 with 99% fiducial limits of 0.28-0.22. The regression of birth weight on gestation was 0.66 lb. per day. © 1954, American Dairy Science Association. All rights reserved.