A New South Wales man who pleaded guilty to animal cruelty over the deaths of 25 ponies has been jailed for at least six months.

Shane Jason Dean was sentenced in Glen Innes Local Court after he admitted 25 counts of committing an act of aggravated cruelty on an animal in February.

It was alleged Dean hired a nine-tonne removalist truck in December to shift the ponies around 440 kilometres from a property in Uralla, in the New England region, to Pottsville.

It is believed he intended to train them in Pottsville, but 100 kilometres into the journey he allegedly got out to check the animals and found them dead or dying for lack of ventilation.

Prosecutors said he then dragged the corpses from the truck, dumping them just off the New England Highway at a truck stop near Glen Innes.

A police tip-off led to the discovery of the dead ponies. They were of various colours and ages and in various stages of decomposition.

Magistrate Mark Richardson sentenced Dean to two years' jail with a non-parole period of six months.

ABC/AAP