GREAT FALLS, Mont. (AP) An 81-year-old Montana man was sentenced Monday to six months in federal prison for illegally using tissue and testicles from large sheep hunted in Central Asia and the U.S. to create hybrid sheep for captive trophy hunting in Texas and Minnesota.

U.S. District Court Judge Brian Morris said he struggled to come up with a sentence for Arthur Jack Schubarth of Vaughn, Montana. He said he weighed Schubarths age and lack of a criminal record with a sentence that would deter anyone else from trying to change the genetic makeup of the creatures on the earth.

Morris also fined Schubarth $20,000 and ordered him to make a $4,000 payment to the U.S. Fish and Wildlife Foundation. Schubarth will be allowed to self-report to a Bureau of Prisons medical facility.

I will have to work the rest of my life to repair everything Ive done, Schubarth told the judge just before sentencing.

Schubarths attorney, Jason Holden, said cloning the giant Marco Polo sheep hunted in Kyrgyzstan in 2013 has ruined his clients life, reputation and family.

I think this has broken him, Holden said.

Holden, in seeking a probationary sentence, argued that Schubarth was a hard-working man who has always cared for animals and did something that no one else could have done in cloning the giant sheep, which he named Montana Mountain King or MMK.

The animal has been confiscated by U.S. Fish and Wildlife Services and is being held in an accredited facility until it can be transferred to a zoo, said Richard Bare, a special agent with the wildlife service.