I am not sure if this device was factory made or something that was made by the village blacksmith Tom Emmett. The reason I say this is due to the fact in all my research on dairy farm equipment. I could not find any reference to such a tool. Mind, I hasten to point out that this was a very modern farm, and at all space between dairy buildings were either finished in concrete or tarmacadam surface, even the holding yard and entry into the milking parlour was finished off with concrete, all of which were washed down with a hose every day.
This of course made it very easy for the cowman to trundle the milk churns when full to the dairy for processing, and return with with clean empty ones to the cowshed.
My drawing uses a full-size ten-gallon churn and the sketch is from memory. It was similar to the farms sack truck or barrow, except that the weight was supported on a hook which fitted into the handle on the churn, and two bars kept the churn from rolling sideways. The original had cast-iron wheels, then if my memory serves me correctly, Ernie Holland, who was the farm engineer at the time, came up with two solid rubber wheels which he fitted. It certainly cured a lot of squeaks and rattles when it was trundled across the pavement to the dairy.