According to the Re/Search Guide to Bodily Fluids (Paul Spinard, 1994), the average man produces about 3.5 mL of semen per ejaculation whose nutritional value is:
(Someday men will have to have this tattooed to the side of their hip, like a can of Coke or a box of Wheaties.)
It looks healty enough per serving size, but when compared to breast milk (which has about 170 calories per cup), semen has about 40% more calories (about 230 calories per cup).