My old farm buildings, with their massive stone and mortar walls, were riddled with rat hidey-holes, while the flagstone floor in the barn was undermined by rat tunnels. Elsewhere on the farm sheds full of hay and straw bales were ideal habitat for such vermin, while stores containing animal feed and barley ensured they were always well fed.

In common with many other farms at the time, ours had a large population of cats that were supposed to hunt and kill those unwelcome rodents. The reality was that they were probably as big a nuisance as rats.

Cats used to be allocated a large dish of milk at milking time. They also had their rations supplemented from the bucket that carried household scraps mixed with dog meal to the sheepdogs.

Despite being well-fed and able to snack on a large population of tasty rats they were always on the look-out for the chance to break into the farmhouse in search of better fare. They watched unseen as you went in or out of the house, and if the door was inadvertently left slightly ajar they were in, in an instant greedily devouring any goodies left lying on kitchen units or tables.

Another downside of cats is that they can become infected with a disease called toxoplasmosis. It's passed on to sheep through feed contaminated with cat droppings, causing them to abort their lambs. The chances of that happening are greatly increased by a cat's distorted perception of hygiene whereby it buries its excrement in heaps of grain and other feedstuffs.

Another drawback with farm cats is that, under the right conditions, they are almost as prolific as rats. A fair number of farm cats were inbred and suffered from a range of debilitating and fatal cat diseases. They also hunted far and wide and many became semi-feral and bred in the wild.

Cats eventually became redundant on my farm after I replaced the old buildings with modern, rat-proof ones and started laying poisoned rat bait around them. That's when I instigated a rigorous programme of neutering to control my burgeoning cat population.

I now see that Scottish Wildcat Action has also started trapping and neutering feral and semi-feral cats in six priority areas in the Highlands in a bid to protect the endangered Scottish wild cat population. It's reckoned there could be less than 300 of these iconic creatures left in Scotland, while there could be over 130,000 feral cats. Interbreeding dilutes the genetics of the Scottish wildcats and transmits fatal diseases.

The "Trap Neuter Vaccinate Return" programme has caught and dealt with over 100 feral cats so far in an area covering close on 700 square miles.

While I applaud that desperate bid to save wildcats, which weigh up to 8kg and live on a diet of birds, rabbits and small rodents, I am becoming increasingly concerned about the possibility of another cat, the lynx, which is double their weight, being released into the wild. They are formidable predators that could have an impact on Scottish wildcats and farm livestock such as sheep.

A couple of years ago 45 members of the Norwegian Farmers' Union, mainly from Northern Norway, visited NFU Scotland at its HQ in Edinburgh. While they were there they gave a presentation about the severe impact of large carnivore predation on sheep farming in Norway. They highlighted that across Norway at that time there were approximately 330 lynx, about the same number of wolverines, 50 wolves and 125 brown bears.

They reported that officially recorded sheep losses to predators in 2014 were 3,895 ewes and 19,671 lambs. They also explained that many sheep farmers in Norway were leaving farming due to the negative impact of predation, and strongly warned the same would happen in Scotland should such predators be introduced.

Against that backdrop, the Lynx UK Trust is advocating a trial release of Eurasian lynx in the Kielder Forest in the Borders. It says the move will generate millions of pounds over a 5-year trial period by boosting eco-tourism in the area.

The problem with lynx is that they are very shy creatures, so tourists would be incredibly lucky to get a glimpse of one, while their nocturnal hunting could leave a trail of devastation for sheep farmers.

Those who advocate the release of these predators naively suggest that sheep farmers could use Llamas to protect their flocks. Llamas do chase foxes away, and may well succeed in warding off a lynx attack, but they would also chase any sheepdogs trying to round-up the sheep.

Please protect us from such foolish notions.