Ovulation Rate in Swine as Affected by Increased Energy Intake Just Prior to Ovulation

Abstract

Thirty-two Chester White-Poland China and 16 Chester White gilts were used in a study to determine the minimal flushing interval required to stimulate increased ovulation rate. Fifty-one Chester White gilts were used in two other experiments to demonstrate the effect of increased energy intake, only, on ovulation rate. Flushing for intervals of approximately 6, 10 or 14 days produced greater increases in ovulation rate from one estrual period to the next than occurred normally in unflushed gilts as a result of one estrual cycle increase in sexual age (increases of 2.8, 3.2 and 3.9 ova, respectively vs. an increase of 1.5 ova for unflushed gilts). There was a tendency for ovulation response to increase with greater length of the flushing period. Gilts fed glucose in addition to a basal ration for approximately 2 weeks prior to ovulation were found to shed a greater number of ova than gilts receiving only the basal ration (2.1 and 0.8 more ova in two different experiments, respectively). In the second experiment, gilts receiving a similar caloric intake furnished by lard were found to produce 1.9 more ova than the basal-fed gilts. The greatest response was obtained, however, when gilts were fed lard at approximately 150% of the caloric intake of those fed glucose—exceeding the ovulation rate of control gilts by 4.1 ova and the glucose and low fat gilts by 3.3 and 2.2 ova, respectively. Copyright © . .