What gland produce prostrate secreation in the semen?

The fluid is derived from the prostate gland. The testicles inject sperm into the prostatic fluid and the cowper's gland shoots "pre-semen" into the urethra before ejaculation. It is extremely slippery and is a lubricant for the semen to flow freely. A rapid climax before excitement can be painful because the cowper's has not yet lubed up the tube.