Maybe if you have any veterinary or zoological training/knowledge/experience you can confirm this for me:
I am under the impression that all mammalian males are quite dependent on female pheromones (in females of their own species) for successful mating. In other words, if the pheromones are not there is sufficient concentration, the male may possibly attempt to mount, but cannot penetrate and cannot ejaculate.
This would suggest that male mammals (1) do not mate with females of significantly divergent species (2)can not mate with other males (so-called animal homosexuality) and (3) rarely or never successfully mate with a female that is not sexually mature and in estrus.
When I say "successfully mate" I mean a completed act of coitus: erection, mounting, penetration, deposit of semen.
Homo sapiens is probably the only exception to this pattern, because our mating is more conditioned on social and psyhological factors, and our minds and wills can dominate our raw instincts.
Is this accurate?
Not exactly. Higher mammals' sexual responses can be classically conditioned with a little effort. Boars, and bulls will mate with an artificial vagina in order to produce semen for artificial insemination. Stallions are kind of sensitive and usually want to go through a courtship ritual, but they can produce for a non-equine as well. They do have to get into the right position to function. Bulls and boars can sometimes be masturbated by humans to produce semen, and the boars will get very fond of the human who does this for them. (And you thought your job was bad!)
Speaking here as a former farm girl who has bred horses. NO familiarity whatsoever with sheep or goats.