Graph showing the change in heart rate after rubber ring castration of nine week old lambs
Mean values in handled control lambs remained between 110 and 115 beats per minute. The heart rate, in treated lambs, increased to a peak of 154 beats per minute at 60 minutes after the rings were applied to the neck of the scrotum and tail. The heart rate remained high (135 to 125 beats per minute, 140 to 240 minutes after treatment) even after the lamb had stopped showing increased activity and abnormal postures and the plasma cortisol values had returned to baseline values (not shown here).
