PSIV-13 Influence of gossypol from cottonseed oil on semen quality in domestic boars as a model for feral hog control.

The objective was to determine the influence of gossypol-containing cottonseed oil supplemented to domestic boars on semen quality parameters as a model for feral hog population control. Sexually mature boars (n = 18) were stratified into 4 treatment groups that were supplemented with cottonseed oil containing varying concentrations of gossypol: 0 mg/kg of body weight (0G), 4 mg/kg of body weight (4G), 8 mg/kg of body weight (8G), or 12 mg/kg of body weight (12G). Oil for each treatment was prepared by mixing gossypol-free cottonseed oil (Riceland Foods, Inc.; Stuttgart, AR) and gossypol-containing cottonseed oil with known concentrations. Treatments were administered for a 42-day period, followed by a 70-day recovery period during which all boars were fed a diet without cottonseed oil. Semen was collected every two weeks during both the treatment and recovery period. Sperm motility, sperm progressive motility, concentration of sperm cells per mL of semen, semen weight, semen volume, and body weight were evaluated. Percent motility and progressive motility were affected by treatment (P < 0.01), time (P < 0.01), and a treatment by time interaction (P < 0.01). Specifically, percent motility and progressive motility decreased in the 4G, 8G, and 12G treatment groups by day 42 of the treatment period and returned to similar percentages as the 0G treatment by day 70 of the recovery period. Concentration was affected by time (P = 0.01) and treatment (P = 0.02), with decreased concentration in the 8G treatment relative to the 0G treatment. There was no treatment by time interaction for concentration (P = 0.93). There was an effect of time (P < 0.01) and a treatment by time interaction (P = 0.02) for body weight, with boars in the 12G treatment gaining less weight over time relative to the 0G, 4G, and 8G treatments. Decreased body weights in the 12G treatment was likely due to decreased intake as a result of palatability issues associated with the high concentration of gossypol fed to this group. There was no effect of treatment (P = 0.28) on body weight. There was no effect of treatment, time, or the treatment by time interaction on semen weight (P > 0.05). There were slight fluctuations in semen volume over time (P = 0.05), but no effect of treatment (P = 0.27) or a treatment by time interaction (P = 0.44). Preliminary results of decreased sperm motility, progressive motility, and concentration in boars supplemented with gossypol-containing cottonseed oil support the potential for gossypol-containing cottonseed oil to be used as a contraceptive in feral hogs