While it's true that horse semen is much more fragile than bull semen, equine artificial insemination has become the norm. It is cheaper to hire a vet to collect the semen and freeze it than the transportation costs involved in shipping a mare across country.
Um, no. Not in race horses.
D. To be eligible for registration, a foal must be the result of a stallion’s Breeding with a broodmare (which is the physical mounting of a broodmare by a stallion with intromission of the penis and ejaculation of semen into the reproductive tract). As an aid to the Breeding, a portion of the ejaculate produced by the stallion during such mating may immediately be placed in the uterus of the broodmare being bred. A natural gestation must take place in, and delivery must be from, the body of the same broodmare in which the foal was conceived. Without limiting the above, any foal resulting from or produced by the processes of Artificial Insemination, Embryo Transfer or Transplant, Cloning or any other form of genetic manipulation not herein specified, shall not be eligible for registration.
The stallion in the thoroughbred breeding programs has to be able to mount the dummy mare for collection and the mare has to be in the room.
Not in Thoroughbred breeding.