In 1950, Camden Park confirmed it was no mere relic of a grand historical past, but the farm of the future. The Rotolactor was the ultimate in modern milking machinery. It was developed in New Jersey. U.S.A. and brought to Australia by Liutenant-Colonel Edward Macarthur-Onslow. The plans were drawn locally and the foundation stone laid in 1950. The building was finished in September 1952.
It was in effect a multi-cow rotary automatic milking machine 18.3 metres in diameter. Its whole circumference was enclosed with glass windows to give natural light, which was supplemented by artificial fluorescent tube lighting for early mornings and winter afternoons. The mechanism consisted of a circular platform mounted on 20, 30.48 cm roller bearing steel which rotated anti-clockwise on 2, 13.6 kg circular rails resting on concrete walls 1.8 metres above the floor.
Normally with the 50 bails operating the rate was 300-375 cows an hour with ten operators. Each cow was stripped of milk in 5 to 7 minutes. The 900 yard cows were mainly fed with concentrates and roughage from the irrigated acres of the Cowpasture Flats bordering the river. Each cow gave an average of 12.5 litres of 4.3 butterfat milk. Menangle became the chief receiving depot.
Pigs were raised on skim milk from the butter factory which until 1947 produced the Estate's own "Laurel" brand butter. During its heyday the rotolactor was a popular tourist attraction. It ceased operation in 1972.
In addition, six model dairies each with its own herd of from 90 to 140 cows, were spread around the slopes of the central and eastern hills of the valley. No. 2, known as the Home Farm is on the north east of the property.
The other activities of the Estate varied from poultry farming and fruit growing to running the general store for Menangle Village. Menangle is no longer a private village, the store is now in private hands, and the orchard is no longer in operation.