Growth of the Swine Fetus

Abstract

Two hundred fifty-four fetuses and 35 newborn pigs of known conception dates were obtained from the experiment station swine herds at the University of Illinois and at Michigan State University. Anatomical measurements made included weight of the body, liver, spleen, kidneys, adrenals, gonads, thyroid, heart, lungs, brain and pituitary; width of the head; and length of body, dissected humerus and the calcified diaphyses or major centers of ossification (measured from roentgenograms) of the humerus, radius, ulna, metacarpals, ilium, ischium, femur, tibia, fibula, calcaneous and metatarsals. Prediction equations developed from Michigan State University data for estimating the age of fetuses from gilts when conception date is unknown are as follows: Ŷ=21.07+0.31 IX, where Y= age in days from conception and X=body length in mm. (crown or frontal crest to anus) for the period from 30 days postconception to birth, and Ŷ=29.00+1.576X, where Y=age in days from conception and X=dissected humerus length in mm. (tuberosity to condyle) for the period from 51 days postconception to birth. Copyright © 1965. American Society of Animal Science . Copyright 1965 by American Society of Animal Science