Twenty-six sheep died and a driver was taken to hospital with head injuries after his stock lorry overturned at Norton, near Presteigne.
There were approximately 75 sheep on the lorry at the time of the incident. The other 49 were moved to a local farmer’s field and were left in the care of a local vet.
The incident happened on the B4355 Presteigne to Norton road, on the Knighton side, at about 1.20pm last Thursday.
Only the stock-carrying HGV, which is believed to have just left Knighton livestock auction, was involved in the incident.
The vehicle left the road and ended up resting on its side with the driver trapped inside.
Firefighters had to release the driver by removing the steering wheel and he was then taken to Hereford County Hospital.
Three fire service crews from Presteigne, Kington and Leintwardine attended the scene, as the Welsh NHS Ambulance Trust and Dyfed Powys Police.
Mark Strutt, station manager for Hereford and Worcester Fire and Rescue, said: “On arrival at the scene firefighters found a stock-carrying HGV that had left the road and was laying on its side, with a trapped driver and approximately 75 livestock.
“Due to the remote nature of this incident, older emergency radios proved unreliable and emergency radio communications were fed through Hereford and Worcester appliances fitted with the Airwave radios.
“Both Mid and West Wales and Herefordshire crews worked well as a team.”
A spokeswoman for Dyfed Powys Police said the road was reopened by 3pm, but it was closed again later in the day for the stock lorry to be removed.
Powys County Council engineers were also called out because the cables of a street light column were exposed and hanging over the road.