Husband and wife Edward, 62, and Linda McCann, 60, and son Daniel McCann, 37, originally from Highcroft Lane in Horndean, and two hired hands, were jailed for a total of 27 years and ten months.
The father and son were sentenced to seven years and seven months, and eight years and six months, respectively at Swansea Crown Court on Monday, December 5.
At an earlier hearing on August 26, Linda McCann was sentenced to six years and seven months, Jack Whitlock for two years and ten months, and Justin Liles for 22 months.
The crown court heard the cannabis factory at the isolated farm – specifically bought for the purpose– was an extension of the family’s cannabis-growing operation in Horndean.
The family bought the farm at Blaenllain in Cwmbach, near Whitland, to grow cannabis five years ago.
Welsh police raided it on October 23, 2020.
They uncovered a large-scale and sophisticated set-up in a barn, which produced herbal cannabis, cannabis resin and cannabis oil.
Edward and Linda McCann, Liles, of Glasfryn, St Clears, and Whittock, of High Street, Narberth, were arrested at the farm.
Daniel McCann was arrested in Portsmouth on February 15, 2021.
During the raid, officers discovered six purpose-built ground-floor rooms in the barn containing cannabis plants with a potential value of up to £460,000.
Upstairs, clothes horses were being used to dry out cannabis and a large quantity of herbal cannabis was found.
Officers also recovered around 80kg of cannabis products worth up to £1.5million
A search of the house uncovered £10,000 cash and a cannabis-infused chocolate bar on the kitchen table.
All five pleaded not guilty but changed their pleas after their trial had begun.