Coolmore has confirmed that 14 of its cattle died last month after the drinking water supply for the animals was disconnected during last month's "intense hot spell".
Coolmore, which is owned and run by the Magnier family, said the incident on one of its farms was "immediately reported" to the Department of Agriculture, Food and the Marine (DAFM), on Tuesday, July 28.
It is understood that the drinking water supply was cut off while the water trough was being cleaned, but was not reconnected.
An investigation into the incident is underway.
In a statement, a spokesperson for Coolmore said: "Coolmore confirms the very regrettable deaths of 14 young cattle during an intense hot spell last month, the hottest July on record".
"The deaths resulted from human error after drinking water was temporarily disconnected to clean the animals’ water trough and a failure to reconnect supplies and monitor the cattle in a timely manner.
"Everyone in Coolmore is deeply, deeply, upset by what occurred and immediate steps were taken to prevent anything like this ever this happening again.
"Due to an ongoing disciplinary process Coolmore cannot comment further at his time," they added.
Coolmore uses precision farming techniques where cattle are mixed to graze in the same fields as their thoroughbred horses.
A spokesperson for DAFM told Agriland: "The department is aware of an incident and does not comment on individual cases".