The Effect of Relaxin and Mechanical Dilation on the Bovine Cervix

Summary These experiments were conducted to determine the possibility of dilating-the cervix to facilitate the ease of collecting ova. The administration of relaxin in conjunction with an estrogen served to relax the cervical muscles. Estrogen alone as judged by the pilot cow gave no cervical relaxation. The minimum dosage of relaxin which gave cervical relaxation was 250 G.P.U.; the optimum, about 1,500 G.P.U. A suitable mechanical instrument was designed for dilating the cervix. However, the instrument must be used with the aid of relaxin when used 5 days post estrus. Histological studies of biopsies from the cervix and uterus indicated no signs of trauma from either the relaxin or the instrument.