[Black Sheep]

Sorry, but please read this: https://www.gov.uk/guidance/slaughter-poultry-livestock-and-rabbits-for-home-consumption

It clearly states that you MUST stun before killing.

Further down the page it says:

"You can use a gun to stun and kill an animal but you must use the correct power and calibre of cartridge for the type of animal. Read the manufacturer’s instructions issued with your firearm to find this information."

So as Sbom says.

[SallyintNorth]

I think I remember there being something in the stun regs about needing to shock a bovine across the heart in addition to across the skull, which you can't do with a shotgun.

My memory can play tricks on me, though, so don't take that as gospel.  I'd check, though, if it were me.

[Blackmyre]

Yes, apparently a gun used appropriately is considered to stun and kill in a single operation. The Humane Slaughter Association has some details. I'm not sure quite how "stun" is defined in that case but it is still legal so, if you had the necessary setup, equipment, skills and confidence, you could use that approach for home slaughter of cattle if you really wanted to.

So that's the actual slaughter but other restrictions come into play. A number of these have already been mentioned in other postings in this thread, and the Tim Tyne piece brings a lot of that information together in a conveniently readable article. All in all they make home slaughter of cattle for human consumption exceptionally impractical in the UK if you want to remain legal. Many of us have looked into it for the same reasons as the original poster but all smallholders I know have concluded the same: far better to find a reputable abattoir not too far away and get the carcases cut & packed professionally. You can then sell or barter some of the superb meat you'll get from a Shetland steer - and there will be a huge amount to get through, even though it's a relatively small breed.