The Collaborative International Dictionary of English v.0.48:

young-begetting \young"-be*get`ting\, adj. (Biology)
   Being the sex (of plant or animal) that produces gametes
   (spermatozoa) that perform the fertilizing function in
   generation, usually male. In contradistinction to female or
   androgynous.

   Syn: male.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

young-begetting
    adj 1: capable of fathering offspring