This problem can usually be solved by dropping a little feed in-front of them. Save these animals for last though, because if you drop feed too soon, ALL of the animals will want some and they will all become agitated. This we call “Feed-n-Breed” and you should begin the insemination’s immediately after dropping the food. Even though the animals are up and eating, they will be distracted from the technicians and hopefully relax their cervix.
I have seen people drop hay, straw, tie a notted rope in front of the animals to play with; basically anything to distract them.. Give it a try!
Also keep in mind that excessive noise, people walking in front of the animals, and especially BOAR EXPOSURE will keep the animals from relaxing!