Right to Information documents released by the Greens have revealed  breaches of the Animal Welfare Act at last year's Harveydale Rodeo, which included the removal of a steer's broken horn without pain relief. 

The incident led Greens animal welfare spokeswoman Cassy O'Connor to last week call for compulsory animal welfare monitors at all Tasmanian rodeos.

Rodeo Tasmania animal welfare spokesman Brian Fish said government monitoring was unnecessary.

''We have no objection for someone being there, but it might be an extra cost for someone that we already have,'' Mr Fish said.

''We already have an arbitrator (the vet), and vets are professional people trained to do the right thing . . . We also have our spectators.  They are not going to stand for cruelty.''

The Animal Welfare Act was changed in 2008 to make veterinarian attendance compulsory.

The FOI documents state the vet knew of the dehorning pain relief requirements but did not comply.

Former Harveydale Rodeo secretary Jacqueline Davey said the 2012 incident was a rare occurrence.

''It happened to fall on its head in the arena . . . I've seen far worse paddock injuries,'' Ms Davey said.

''Rodeos are very proactive when it comes to animal welfare.  We contributed to the current guidelines and we take all precautions to minimise the risk to the animals.''

Mr Fish said he did not consider rodeo events to be cruel, but said there were different perspectives on what equalled cruelty.

Primary Industries Minister Bryan Green said he would be announcing his decision of a current review on the Animal Welfare Act soon.

''I have considered (the) Animal Welfare Advisory Committee's comprehensive report and recommendations, including those that relate to further strengthening provisions for rodeos,'' Mr Green said.