Uterine size in replacement gilts associated with age, body weight, growth rate, and reproductive status

The objective of the present study was to determine the association between the uterine size and age, body weight, growth rate, and reproductive status in Landrace x Yorkshire crossbred gilts. Genital organs from 310 gilts (302.6 +/- 2.9 days of age, 145.2 +/- 1.2 kg body weight) were examined. The gilts were classified into two groups according to reproductive status: non-cyclic (n = 86) and cyclic (n = 224). The uterine weight in non-cyclic gilts was lower than that in cyclic ones (128 +/- 8.1 and 694 +/- 17.9 g, P < 0.001). Likewise, the length of the uterus in non-cyclic gilts was shorter than that in cyclic gilts (123 +/- 2.9 and 252 +/- 4.6 cm, P < 0.001). The weight of the uteri correlated with the body weight (r = 0.48, P < 0.001) and growth rate (r = 0.33, P < 0.001) of the gilts but not with their age (P > 0.05). For every 10 kg increase in the body weight of the gilts, an increase of 67 g in uterine weight (P < 0.001) and 21 cm in uterine length (P < 0.001) was observed.