The Royal Highland Show, held at Ingliston next to Edinburgh Airport, begins its four-day run on Thursday and, as always, the weather is the big lottery for the organisers.

It's the shop window for Scottish agriculture and this year celebrates its 175th anniversary.

Thursday and Friday are favourite days for farmers, as they tend to be quieter allowing them to do business at the various trade stands. At one time a lot of machinery was bought at the show, but nowadays there is less on display as modern farmers prefer to make their decisions on purchases after seeing how they compare with other makes and models at specialist working demonstrations.

Thursday and Friday are also the days when the livestock are judged. There's nothing better than spending a couple of hours watching the judges picking the prize-winners from the various classes. Hundreds of shrewd, experienced eyes are watching and judging the judge's ability, as well as selecting their own preferred animals.

Most farmers dress up to attend the show, but I have to say that the sheep and cattle put them to shame. White-faced sheep have chalk and talcum powder on their faces to make them look whiter. Blackface sheep have their horns sandpapered and oiled, their heads glistening with the special dressings the showmen use. And every sheep has had its fleece brushed and trimmed to make them look as big and meaty as possible.

My next on visit is invariably the cattle lines to watch the stockmen wash and shampoo their beasts, before blow drying and grooming them. Looking at the rows of massive, well-bred, perfectly trained cattle always made me think how scrawny and wild my own herd was - but then I remembered the long, hard hours the dedicated stockman put in to get their beasts into show shape.

You really have to admire cattle and sheep exhibitors for their dedication, as well as those who bring out poultry, goats and horses. It's not the prize money that drives them on, but the sheer satisfaction of winning. It's not just a hobby, but a way of life for many and the summer season of shows constitutes their holidays.

Showing often demands long-term commitment. Breeders have to put their money where their mouth is when they select livestock at sales. All too often, an outstanding looking animal fails to breed as expected, but top breeders seem to select a higher proportion of good breeding livestock compared to mere mortals like myself.

When the progeny are born, the breeder is again put to the test when he has to select potential prize-winners and grow them out. Some have the gift of seeing something special in an animal that might appear to be little better than an ugly duckling to others.

Potential winners have to be patiently trained to walk or stand correctly so they always look their best and catch the judge's eye, It takes a lot of patience to build up that special relationship between animal and handler. Finally, in the run up to the show there are hours of meticulous washing, trimming and grooming to have the animals looking perfect.

The Highland Show is also seen by agri-politicians as a wonderful opportunity to make announcements to the press.

Europe's leading farm official, EU Agriculture and Rural Development Commissioner Phil Hogan will be visiting the show for most of Thursday. That will be followed by a visit on Friday to Garvald Mains near Haddington, where Robert and Gavin Hamilton produce cereal, beef and lamb. So those visits should generate plenty of press briefings on the failings of the Common Agricultural Policy (CAP) reforms and opportunities to photograph who said what.

Although Thursday and Friday may fairly be described as the Farmer's Days, Saturday and Sunday definitely belong to families. There's so much to see and do that even the most energetic families are exhausted by the end of it all.

For shopaholics there are supermarket stands, while others sell plants, craft work, clothing, furniture and just about everything else. My favourite is the massive food hall where all kinds of food and drink can be sampled and bought.

As the day wears on it's nice to sit and enjoy an ice cream watching a shearing competition or blacksmiths making horseshoes, or lumberjacks racing up and down massive pine poles, or carving birds and animals out of logs with chainsaws.

So here's hoping the weather is favourable.