The main autumn sheep sales are mostly held in August and September, so they are now over for another year.

First to go through the auction rings are store lambs. They are half-grown ones, mostly wethers (castrated male lambs) off poorer grazing, that are bought by those with better land to grow on and fatten. Ewe lambs to be kept for breeding are more-or-less sold at the same time as the stores.

The main lamb sales are then followed a little later by sales of draft ewes, which are older ones that are sold onto better, kinder farms for another breeding season or two.

At one time there were large sheep sales held all across Scotland, but they are now just a fraction of what they once were. For instance, in 1991 United Auctions sold 41,000 North Country Cheviot lambs through two auction rings in Lairg in one day - ewe lambs through one ring and store wethers through the other.

Bumper sales like that, and many others in the 70s and 80s, regularly saw between 25 and 30,000 lambs go under the auctioneer's hammer.

Sutherland, in common with many other areas of Scotland has seen breeding ewe numbers decline to under half of what they were in the 90s.

Large-scale tree planting, particularly in the 60s and 70s, displaced a lot of hill sheep. Lack of profitability saw other breeding sheep removed from hill land in favour of subsidised environmental schemes. Many hill flocks were sold off to increase revenues from more lucrative grouse shooting or red deer stalking, while still receiving the Single Farm Payment.

Compounding the shortage of store lambs is the trend towards farmers fattening their own lambs rather than selling them as stores, in an attempt to improve margins. Perhaps I should be using the phrase "finishing" rather than "fattening" , as that probably conjures up a better image in the minds of the majority of consumers who prefer lean meat.

Anyway, there are many different ways to finish store lambs to be sold in their prime over the winter. The most popular method for hill farmers is to rent grazing from the likes of a dairy farmer for about 70p per head per week, or between £10 and £14 per head for typical finishing periods. When you add the costs of the additional transport involved, medicine bills and losses from deaths you can see it's not a cheap option. It can also be a bit of a gamble, because it doesn't always follow that selling finished lambs will leave a profit on the prices that could have been achieved in the store ring for a lot less hassle.

Others hopper-feed their stores at home on a cereals based concentrate that supplements the grazing. That's where lambs can help themselves to concentrates offered in small tin shelters that protect the trough and hopper containing the feed from the elements. Again it's not a cheap option and has the added disadvantage that the lambs can get badly soiled by the mud that is generated around the feeders in wet weather.

Traditionally, many farmers grew specialist crops like stubble turnips, forage rape, kale or swedes to finish lambs on. Rising costs and labour shortages have seen a dramatic decline in the acreage of such forage crops being grown.

Swedes, or neeps as we call them, can be sown by placing individual seeds at the correct spacing to avoid the laborious task of thinning them with hoes, while weeds can be controlled by spraying selective herbicides.

Still, other tasks remain, like regularly moving the temporary fencing that regulates the lambs' access to the crop and avoids waste.

I remember when I was at college some hill farmers pioneered a technique of intensively finishing their lambs indoors. It seemed to work reasonably well at the time, although many have given it up due to increased feed costs. The secret to success was to make sure that the lambs were well grown before they were brought indoors.

Some discovered that they could increase the growth rates of their lambs indoors if they sheared the wool off of them. That reduced the risk of heat stress, which can be a problem when lambs are housed and fed a high cereal diet. It also encouraged them to eat more which finished them quicker reducing the number of days to slaughter.

I tried many different systems of finishing my lambs when I was farming, and although I sometimes made a good return, more often than not I found they were not worth the extra hassle and expense.