Bovine Crown Rump Length Calculator Information

Graphs shown are from:

Physiology of Reproduction and Artificial Insemination of Cattle. G.W. Salsbury, N.L. VanDemark, and J.R. Lodge. Freeman and Company, San Francisco, 1961 and 1978. p153.

The data was from:

Foley RC and Reece RP. 1953. Histological studies of the bovine uterus, placenta and corpus luteum. Massachusetts Agr. Expt. Sta. Bull. 468.

Winters, LM, Green WW, Comstock RE. 1942. Prenatal development of the bovine. Minnesota Agr. Expt Sta. Tech. Bull. 151.

Melton AA, Berry RO, Butler OD. 1951. The interval between the time of ovulation and attachment of the bovine embryo. J. Animal Sci. 10:993-1005.

Swett WW. Mathews CA and Fohrman. 1948. Development of the fetus in the dairy cow. U.S. Dept. Agr. Tech. Bull. 964.

The equations are:

FA=Fetal Age (days); CR=Crown rump length (cm)

FA=((-0.012 *CR * CR) + (3.644 * CR) + 29.425)*10)/10

CR=((.001 * FA * FA) + (0.192 * FA) - 5.844)*10)/10