Read more: Farmer shocked after 100 cattle and sheep rustled
The post, on the official Farmer’s Journal Facebook page, has already generated over 15,000 likes, over 500 comments and almost 4,000 shares.
Many farmers are offering livestock, while others are offering trailers and transport.
Christa Dillon, Niall's wife, replied to the post and wrote: “I just can't believe such kindness and generosity. I want to thank you so sincerely.
“I'm beyond words to express my gratitude-to you and to the thousands who are rowing in behind us. I have never been so proud to be in agriculture in Ireland.
“Thank you. Just THANK YOU. This means everything.”
Another wrote: “What a very kind and generous offer Jim, myself and my husband happy to give a calf too. Hope this will inspire others to give a calf also.”
Those who don’t have livestock to donate offered other incentives to keep the generous trend moving: “I haven't any calves to donate but I will give 100 small square bales of hay to anyone who can supply a calf.”
And another posted: “I have an eight channel CCTV system with day/night vision cameras which l haven't used and would be happy to give them to you.”
Read more: Farmers are being 'wiped out' by cattle rustling gang
Niall Dillon told the Irish Independent he believes thieves must have been watching his movements and his premises in Cornaher, Kilbeggan, Co Westmeath before the robbery.
The first sign he had that anything was amiss was when he noticed that the lock had been cut on the gate leading into the farm that he had rented 4km from his home.
"Like a lot of people I would have thought that a lock was enough," Mr Dillon said. "I noticed nothing over the past few weeks but they have to have been watching the place."
Gardaí have appealed for anyone who might have seen any unusual animal transport activity in the area to contact them.
"There were four cattle in the field and that is all. The shed was empty," he said. "Everything was gone." He said neither of his neighbours were close enough to have heard any activity.
Mr Dillon said CCTV footage from the Tyrrellspass area had captured a lorry and single trailer, and also a lorry with a double-decker trailer that may potentially have been involved.
"They were large lorries with plenty of capacity and gardaí are searching CCTV on routes that they may have taken," he said, adding it was difficult to tell what the final market was for the animals.
The Irish Farmers' Association (IFA) national livestock chair Henry Burns said such a large volume of animals "cannot have vanished into thin air" and it would have had to have been planned.
All were tagged and are fully traceable under the Department of Agriculture's system. The animals taken included nine cows and nine calves, and included around 15 Charolais continental crossbreeds. Gardaí said it was unusual for such a large volume of animals to be taken.
Figures from the Department of Agriculture recently showed that 59 cattle were reported missing from farms between January and June 9, with 146 stolen during all of 2014.
Paddy Donnelly, the IFA's Westmeath livestock chair, said it would have been a "major undertaking" to round them up.
Paul Daly, a neighbouring farmer and councillor, said it was a worry for those in the area and for "all farmers in rural Ireland when such a thing can happen in the dead of night".
Anyone with any information has been asked to contact gardaí at 090 6498550.