When Mr Harty worked at Granard Mart in the late 1980s he witnessed huge numbers of heavy cattle going through the sales and excellent demand from Northern Irish buyers who made a big contribution to the return for farmers.
"Now we are suffering from the demise of the Northern Ireland trade," he says. "In the North our cattle are not recognised as either Irish cattle or English cattle – that is wrong. It has killed the cross border trade and it has contributed to our marts becoming very store cattle orientated," he says.
He recalls other challenges which have left a permanent mark on the business.
"Two of the biggest upheavals to the mart trade were BSE in 1996 and Foot and Mouth Disease (FMD). FMD closed the marts for four months from February to June and destroyed the sheep trade in the marts," he says.
"Up to 2000, Nenagh and Birr marts were packed with sheep each week. There is no sheep sale at either centre now. Twenty years ago it could never have been envisaged that there would be no demand for a sheep sale at Nenagh."
He also argues that the QA (Quality Assurance) criteria imposed by beef processors are unjustified and a cost too high to be accepted by either farmers or the marts.
"There is not a level playing field for farmers to sell finished cattle through the marts," he says. "The movement and residency restrictions imposed by the factories for QA is crazy. It's costing farmers a lot of money.
"I saw a lot of cattle in the ring the other day, all with three movements, except one with four movements. We have to show the longest movement on the board and straight away I could not get a bid for them.
"The cattle were discounted because they could not get the QA bonus. It is definitely a penalty that has been imposed on farmers by the factories and has to be looked at because it does not make any sense at all," he maintains.
"If the animal has been on a QA farm for 70-100 days – all those farms are being visited and inspected – that should be sufficient for an animal to go into any outlet. The movement restriction should go and let farmers get the value of their cattle."
The doubling of the QA to 12c/kg a year ago has compounded the situation.
"It has become another form of slaughter premium in favour of the factories," says Mr Harty. "Farmers tell me they are going to lose up to €100/hd by putting finished cattle through the mart when they combine 12c/kg QA and 20c/kg breed bonus.
"Even if the best customer at the ringside buys them he will not qualify for either – that's €100/hd gone off them cattle. It is denying the farmer the choice to sell through the mart."
He predicts that a decade from now there will be fewer animals going through the marts if the present trend continues.
Factory-imposed regulations have killed the throughput for finished cattle and farm-to- farm sales for store cattle are increasing, but "farmers have to come to the mart to see what their cattle are worth."
From the mart management perspective, he says compliance with regulations is effectively "unpaid work for the Department of Agriculture that takes a huge chunk of our time and has to be carried out to the highest standard."
On the plus side for farmers, he says the new financial regulations "means that the mart in the only place in Ireland where farmers are absolutely guaranteed to get payment", because by law the mart must maintain sufficient funds in the client account at all times to meet the cheques.
"It is not simple. It is alright for marts that are financially strong even though it is a challenge for weaker marts – but it is the law and it is a safeguard for farmers," he says.
And it's not all about prices and regulations; Harty, a part-time farmer himself, believes that marts are the last social outlet for farmers.
"The creameries are gone and the local pub is gone for a lot of them. The amount of older rural farmers in particular that won't miss a mart day is truly amazing," he says.
"They'll have a cup of tea or lunch in the canteen, meet the people, and chat for an hour – it is their day out for the week".
A member of Fine Gael, Mr Harty is the current chairperson of the party's Co Tipperary constituency organisation.
For relaxation he follows the fortunes of Toomevara GAA with whom he hurled as a minor.
Politics, farming issues and the GAA are all entwined in his days at Nenagh Mart which is as important to the town and its hinterland as the fair days of old.