I LENT my younger grandson one of my shepherd's crooks as a prop for his part in the school nativity play.

It had stood neglected, along with others, in a corner of my office since I retired from the farm.

Like Moses without his staff, a livestock farmer without a stick is unthinkable. They come in various shapes and sizes from rough-looking cattle herders –that are simply sticks, or even lengths of plumber's plastic pipe – to the fancy crooks we use on days away from the farm.

While a stick is an optional extra for working with cattle, crooks are an everyday essential for shepherds. They give support and leverage when climbing steep braes, steady you on your descent, and are in effect a third leg, as well as being vital for catching nimble sheep. Younger, athletic types can catch sheep with their bare hands, but it isn't easy and you often end up with just a handful of wool.

With skill and the help of a collie, however, you can easily catch a sheep by the neck with a crook.

The idea is to stand about a crook's length away from a fence or drystane dyke. The sheep is then manoeuvred and encouraged to run through the gap between the shepherd and the fence, when it is caught by the crook.

Another type of crook, called a leg cleek, catches sheep by the joint of the back leg. Better still, unlike neck crooks, that require the shepherd to exert some strength to restrain heavy sheep struggling against it, those caught in a leg cleek tend to back towards the shepherd and consequently are easier to hold on to.

Made from a straight, stout hazel shank, crooks have a shaped and carved ram's horn handle securely fitted at the top. Some are ornate works of art that are only used at markets or agricultural shows, but everyday working crooks are plain and strong.

Ram's horns and stout, straight hazel shanks are very scarce resources.

Only horns from a mature, dead ram will do. After drying and curing for a couple of years, they are shaped by gently heating over an oil lamp – hard horn becomes malleable when hot.

I used to make crooks as a hobby when I was a young man. The idea is to crush the hot horn in a vice in such a way that the hollow in the centre is squeezed and it becomes solid.

Then the curly horn is twisted and set between metal plates in a vice so that when it cools it is no longer a spiral shape, but flattened into the same plane.

Finally, they're filed down, fitted to the shank, carved, polished and varnished.

Some are real works of art. Thistles, collie dogs, pheasants, grouse and fish are just some of the things carved on a fancy crook. Often the farmer's name and his farm are engraved on the side.

Good horns are scarce simply because, with the decline in the number of hill sheep, there aren't as many horned rams about as there used to be. Worse still, some shepherds set the horns on a young sheep to the desired shape in preparation for the autumn sales by heating them.

Such horns often develop soft or hollow areas beneath the surface as they grow and develop, and are difficult to make into nice crooks.

Good hazel shanks are often just as difficult to come by, as they are used by other countrymen, such as gamekeepers, for such things as pegs for setting snares.

Shanks are best cut in the late autumn or early winter when there is less sap in them.

They are then slowly dried in bundles in the rafters of the workshop for a couple of years.

If shanks are not thoroughly dried before they are fitted to the crook, they will twist and warp.

Those that are not perfectly straight after drying can be straightened by heating over a steam kettle and then being held firmly until they cool.

Too often in the past, I have had the disappointment of finding a nurtured hazel shank, that I had watched grow to perfection, taken by someone else before I could harvest it. I suppose that's where the saying, "you should aye cut a stick when you see it", comes from.