I agree we've all heard these stories and generally there's a reason stories like that get around...because they have some truth to them.
I know two well known farms that had their stallions checked and not one of the stallions semen was any good after 24 hours.
I never tested mine, but then again, I do not stand my stallions to outside mares at this time.
They say it is very effective and the reason people say it isnt is because they are resistant to change and things they dont have knowledge of
Not everyone who is into Mini's "don't have the knowledge". Some Mini people came from breeding successfully other breeds and have used only shipped semen to breed their mares.
I bred Morgans for 10 years and always used shipped semen, I bred several mares each year, so I guess I know a little of what is involved. It is VERY expensive (was even then, 5+ years ago)
The vet will have to make several trips out to the farm to check to see how the mare is getting alone and where she is in her cycle, (a few ultrasounds there), then once she looks like she is ready to release an egg, the vet pops her with a shot hoping she will ovulate after 24 hours. The mare owner has to call the stallion owner and have the semen delivered overnight.( the cost over 5 years ago was $250 to have the semen shipped (every time semen is called for, no matter how many trys) plus $50 to ship the empty container back.) Then the vet has to come back and insert the semen into the mare. Usually there are two bags shipped. One is used the first day, the second used the second day. EAch day the vet checks to see if the mare has ovulated. Then 18 or more days later, the vet has to come out again to ultrasound the mare to see if she took, if not, the vet will pop the mare with a shot to make her recycle and you have to start all over again. Now, where I live it costs $55 for a barn call, plus $60 for an ultrasound, so $115 every time the vet comes out to check the mare. That does not include the shots or inserting the semen. I am talking about $1000 or more per try.
Often it takes more then one try, many times at least 3 tries before the mare is confirmed in foal ( I used a nationaly well known vet who specialty was breeding, AI and embryo transfers and most of the time it still took more than one try). In many parts of the country, vets are just not experienced enough. Also Minis are more predisosed to having silent heats, or not ovulating correctly while having a foal by their side.
On the stallion owners side, one also has to have a vet that is ready to come out at a moments notice to collect the stallion ( one needs a mare that is in heat at that moment, or the stallion trained to mount a dummy) and get the semen prepared and ready for shipping and then get the semen to the overnight service by a certain time. (also, the stud owner will need to have several specialized shipping containers for keeping the semen properly cooled (also very expensive). Then they have to depend on the mare owner shipping the container back to them the very next day so that they have it for future calls.
During breeding and foaling season vets are very busy and it is not always easy to get a vet to come out to ones farm on a moments notice to collect the stallion. Most farms that offer shipped semen are able to collect and prepare and ship the semen themselves. Can you imagin how upset a mare owner would be if the semen did not get to its destination on time? With the $1000's the mare owner has already invested just getting the mare ready to accept the semen?
Again, it will cost aproximently $1,000 per try, not including the actual stud fee.
I for one, being a stallion owner, would not want the responsibility of shipping semen unless I had a stallion who was very much in demand.(otherwise finacially it would not be worth it) Then, how often would one be able to have the stallion collected and semen shipped and have viable semen at the other end. Many stallion's semen may start out being very good, but the mobility will dwindle as the stallion is over used. What happens when you have several farms calling you the same day asking for shipped semen?
These are all things a farm need to think about before they decide to stand their stallion for AI breedings.
In the big horse world many top stallion owners have their stallions standing at stallion stations where the station is well prepared to do that kind of thing and usually has a vet working there. That too is a very big cost for the stallion owner. The average small farm with 1 or 2 stallions just can not make it finacially worth their while to ship semen. Plus, then they also do not have the stallion on their farm breeding their mares.
For every mare that is booked to that stallion, he needs to be in prime breeding shape (thus not breeding owners mares). If a stallion has bred an owners mare naturally in the AM and then the stallion owner gets a call for shipped semen, the chances are the semen will not be as viable being collected and shipped that day.
Many, many things to be considered by both the stallion owner as well as the mare owner.