Search on here and you will find a lot of information as this question has come up numerous times. Here is what I generally do when sending something off like that. I have the animal appraised, a fair value for that animal. I expect animals returned to me in the condition they left in, so I generally take pictures and include them in the contract. I think both you and the person leasing the bull should have vets examine the bull for any underlying issues and a breeding exam. My contracts state that the person leasing the animal are responsible for providing and paying for the care of the animal, this includes feed bills, board, and veterinary expenses incurred while they have them. If the animal does not come back to you in the same condition as when he left, then there needs to be veterinary inspection. If the animal was compromised by uncontrolable circumstances, then the person leasing is not responsible for any costs of replacing. However if the animal was not returned in same condition and it was somehow due to negligence of person leasing, then they are responsible for the costs of returning the animal to proper condition. If the animal is unable to be rehabilitated, then the person leasing is responsible for the costs of replacing him with something of equal or greater quality. I have never worried so much about insurance because in these cases they always have uncanny ways of getting out of settling anyway, but I know some people that require the people leasing to provide proof of an insurance policy that would cover the bull if something happened.