No personal experience, but there are certain veterinary practices and stud farms that will do this.
I did witness a collection at a stud in the USA. It was a very slick operation. The stallion was trailered over, he came into the covering yard and the mare was brought in. The semen was immediately viewed under a microscope (we had a little look) and then they did what ever they had to do.
There must have been some sort of hygiene rules and regulations I imagine, but we weren't told.
thanks OrangeHorse, yes tests are carried out for equine transmutable diseases, and motility of sperm, whether or not it freezes well, but i am interested in quality of procedure and competence of persons carry out the process from start to storage, and handling of the stallion during collection, don`t want any rough arxe pulling him about!
Depends where in the country you're based. I agree Twemlows are excellent but are miles from me. I use Rossdales in Newmarket for my stallion and they are excellent.