Museum and gallery staff put their favourite artefacts on display.

This plaster cast model of a shorthorn bull has become one of our most popular items. I remember the donor rather diffidently offering it to the museum a few years ago.

She had bought it in the 1930s from an old man who ran a china repair shop in Fetter Lane, London, with the story that it had been on display at the Great Exhibition in Hyde Park in 1851. This is unlikely, for the model is actually half a century older than that.

It is a significant artefact from a period when development and experimentation were starting to produce the definable characteristics of separate breeds of farm livestock.

The shorthorn model was made by the artist George Garrard (1760-1826), who announced in 1798 that he intended to offer for sale sets of such models, all at the scale of 214 inches to the foot, for the price of two guineas per animal.

Over the following decade, 21 breeds of cattle, sheep and pigs were represented in this way, and an accompanying book gave, at least for the cattle, a full picture and description of each individual animal.

From this we learn that our model is of a Holderness bull, the breed we now refer to by the more generic term of shorthorn and which was then the prime focus of improvement work by famous breeders. This particular beast, Garrard tells us, was part of the royal herd at Windsor. The meticulous listing of dimensions reveals it was 7ft 7in long and 7ft 2in around its largest circumference.

Garrard hoped that the accuracy of these models would give livestock breeders and judges a standard by which they would be able to identify the best stock. For us, they provide a rare example of a faithful, three-dimensional view of farm animals from the age before photography.

Roy Brigden is keeper of the Museum of English Rural Life, University of Reading, Whiteknights, POBox 229, Reading RG6 6AG. Tel: 0118 931 8660