Abstract
Morphological changes in umbilical cords of 884 piglets were examined in the present study with lapse of time at their neonatal stage. The length, diameter, and moisture content of umbilical cord of each of the newborn piglets were in the range of 31.2±13.0cm, 7.28±1.09mm and 92.9±1.2%, respectively. Of the postnatal changes in the umbilical cords, rapid shortening in the length of umbilical cord was noted up to 4 hours of the neonatal stage, with significant differences (P<0.01) in the piglets with a length of umbilical cord at birth over 11cm from that of the others. Especially, the rate of shortening of the length of umbilical cord was the highest (into 76.2%) in those with a length of umbilical cord over 41cm, whereas the rate of shortening was so insignificant as by 18.5% in those with a length of umbilical cord less than 10cm at birth. The shortening of the length of the umbilical cord was not so significant after 4 hours from birth. The diameter of the umbilical cord was 2.69±0.51mm at 12 hours after birth with hardly any changes thereafter. The moisture content decreased into 46.6±9.5, 17.9±1.9 and 17.6±1.5%, at 6, 12 and 18 hours after birth, respectively. In conjunction with the relationship between the angle of flexure and the moisture content, the content was 58.7, 39.6 and 21.1% for the angles of 80°, 40° and 0°, respectively, showing a significant correlation (P<0.01, r=0.852) between the two parameters.
