Only when the prostate gland seems completely drained, should a milker perform the milking of the bull’s seminal vesicles. This is not something a milkee can do alone. Most people have a thumb long enough to milk their prostate gland, but only a few can reach his own seminal vesicles, which lie above the prostate gland. The seminal vesicles play a great role in male semen production: they secrete approximately 60% of the seminal fluid. This helps us understand the importance of their drainage.
The seminal vesicles massage is a very strange feeling, and it can produce many types of emotions or reactions. If the bull is really aroused, it can drive him to the orgasm. So it is important to proceed to milk these glands only when the prostate gland has been already milked. Because the prostate gland requires some minutes to become engorged again, this helps to prevent an involuntary orgasm.
A good description of the location of the seminal vesicles can be found in Benders’ article (pics can be found on this page of Wikipedia). It’s helpful if the milker has long fingers. It’s better if he use two fingers, index and middle, together. When the fingertips go beyond the prostate gland, they reach the seminal vesicles. They are two clearly recognizable bulges which, starting from the prostate gland, spread sideways and more deeply. The touch should start from the top and moving towards the prostate gland. A light touch is sufficient to squeeze the fluids of seminal vesicles into the urethra, so don’t be surprised if the first time you try this kind of massage you’ll see thick drops of seminal fluid flow out from bull’s penis before you realize that you are touching just his seminal vesicles. When the first drops have spilled out, you can milk these two glands with more vigor. It requires only a few minutes since seminal vesicles can be drained, so you can obtain their milk more quickly than from the prostate gland. They should produce at least half of the seminal fluid contained in a natural ejaculation.