Here's another related post on Sukhra:viewtopic.php?f=40&t=5330&p=58856&hilit=Kita#p58856
Although I believe that female Sukrha is called Raja.
And to quote Namdrol's quote from an earlier post:
"The final state of the semen (sukra) of the physical constituents (saptadhātu) is the supreme one called "ojas"; located in the heart, pervading the entire body, and causing longevity, and causing a radiant complexion and a brightness."
Just want to add here that this doesn't contradict that physical semen as the final product of digestion can be transmuted into subtle matter or energy (as I've mentioned before, Ojas we could say is both physical and subtle).
And from what I've learned Semen/Suhkra can indeed be transmuted into Ojas; however that if semen sits untransmuted in the body for too long, it dies (i.e. no longer capable of creating life externally or internally), and would therefore become a waste product in this latter case.
Nevertheless, there is not necessarily any need to ejaculate it if it happens to become a waste product, because it will come out on its own with our urine during defecation, or even during urination alone. At the very least, Sukrha can also be absorbed back into and dissolved in the bloodstream. Also, live semen could escape along with stagnant semen during ejaculation, and also the muscle spasms of orgasm are just as damaging to our practice as loss of semen (I'd posted a link about this on the first page of this thread).
Now if we are transmuting properly (and retaining the semen, but not forcefully) and/or enough (whether through Pranayama, Yantra Yoga, Tummo, or Karmamudra practice), the Sukrha will not have enough time to stagnate, die, and become a waste product, as it will instead be continually transmuted into Ojas, more or less right after it is formed after digestion; and will strengthen the Nadis and various glands and chakras in the body.
Some may not agree with this, but it is the only logical explanation behind some schools of Hindu, Taoist, and Buddhist Tantra's injuctions (such as the Gelugpa) to not ever
ejaculate the semen through orgasm.
In my own experience, it is easily possible to at least go for months without releasing semen (the Dalai Lama said that Initiates of Tantra should not lose semen even during dreams, which is easier to achieve for those practicing Karmamudra than it is for celibates), and with only losing very little semen during micturition on occasion.
In my own experience as well, it is also much more difficult to overcome the affliction of lust if we are intentionally losing the semen.
People often ask if we'll become frustrated by conserving the semen; but really one finds that in conserving the semen, sometimes we actually end up looking for ways to increase our sexual fire (strong sexual fire in itself is not necessarily lust, by the way) even more, through various herbs, eating red meat, etc.
But if we eat healthy (mostly organic or at least all natural), get plenty of exercise, and do transmutation practices regularly; we can balance everything and have a strong libido without succumbing to the affliction of lust, the latter of which we ought to transmute into chastity (not to be confused with celibacy).