Semen contains sperm and nutrients to maintain the sperm and nourish it.
So as a default, it is technically good for you.
But there's no where near enough content in it for it to be considered on the level of subsistence in any stretch of the imagination unless you literally consumed unhealthy amounts of it.
One of the primary contents of semen is essentially sugar. Hence why each sweeter things often makes the taste of it become slightly sweeter.
Long answer short, it's technically good for you, but not in any substantial quantity.