Background and Aim: Gossypol, a cotton seed derivative, is well known for its reversible antifertility in male reproduction across species. Its antifertility and reversibility effects on male reproductive function vary among species in dose-and time-dependent manners. In this study, the antifertility potential of gossypol in pigeons was evaluated for the first time to determine whether it might be used as a dietary supplement for pigeon population control.

Materials and Methods: Male pigeons were assigned into three experimental groups: The gossypol-treated group (n = 12), the sham control group (n = 6), and the negative control group (n = 6). There were two experimental periods: A gossypol-feeding period of 28 days and a gossypol-free period of 28 days. During the gossypol-feeding period, birds in the gossypol-treated group were fed 4 mg of gossypol extract per day. Birds in the sham control group were fed 0.5 mL of mixed ethanol and sunflower oil, while those in the negative control group were fed 0.5 mL of phosphate buffer saline. After the gossypol-feeding phase was completed, all remaining pigeons in all groups continued to receive their regular diet for an additional 28 days (gossypol-free phase). The body weight and semen quality of the birds in the experimental groups were compared to evaluate gossypol's antifertility effect.

Results: In the gossypol-treated group as compared to the control groups, the percentages of sperm motility and viability were significantly lower at 21 days, and the percentage of normal sperm morphology was significantly lower at 28 days during the gossypol-feeding period. After gossypol withdrawal, these antifertility effects were resumed and reached a comparable semen quality to the control groups within 14 days.

Conclusion: Gossypol supplementation (4 mg/day for 28 days) could lower male pigeons' reproductive performance in terms of sperm motility, viability, and sperm morphology. Such infertility was, however, reversible within 14 days after gossypol withdrawal without any side effects on the pigeons, suggesting its application as a safe contraceptive feeding for male pigeons.

Keywords: gossypol, pigeon, sperm morphology, sperm motility, sperm viability.