More than 30 dead horses were found at the site
A court has ordered 29 donkeys and ponies be returned to a family accused of causing unnecessary suffering to more than 100 animals in their care.
RSPCA staff and vets removed 125 animals from Spindle Farm, Hyde Heath, Amersham, Buckinghamshire, in January.
Oxford magistrates heard the family consider some of the donkeys and Shetland ponies to be pets.
James Gray, 44, Julie Gray, 40, Cordelia Gray, 19, and Jodie Gray, 25, all of Spindle Farm, deny 12 charges.
Deputy District Judge Sandeep Kainth agreed to return the pets to the family but rejected their application to have the remaining 82 animals returned.
These animals will instead be sold at auction in May in Warwickshire.
The RSPCA had argued that it should be allowed to oversee the re-homing of the animals in order to safeguard their future welfare.
But Judge Kainth said the donkeys and Shetland ponies had to be returned to the Grays, "as there is no evidence to show they are in any danger".
RSPCA inspector Kirsty Hampton said the decision to return the horses to the Grays was "devastating".
She also voiced her concern that the remaining animals would be sold on.
"We had hoped that the court would ask us to seek new owners for them who were guaranteed to provide for their future welfare," she said.
"An open sale to an unknown bidder means that we cannot be sure of the level of future care they will receive. Hopefully they will be bought by people who will properly care for them into old age."
The Gray family, and a boy, 15, pleaded not guilty to charges of causing unnecessary suffering to and failing to meet the welfare needs of a total of 125 animals, removed between 4 and 12 January, 2008.
Their case was adjourned until 28 April when it will be heard at the same court.
The maximum sentence for each of the charges is six months in prison or a £20,000 fine.