John, at this point I think we should put a full stop after all that scatology. Or at least a colon.

Roger,
It works fine up in my neck of the woods.

The Cambodian waitress served chow
That in previous days said “meow”;
But her sinuous grace,
And that smile on her face
Had me wolfing it down, anyhow.

Jerome,

Regarding watered milk, Thoreau remarked that finding a trout in the milk was a good example of when circumstancial evidence ought to be admissable.

Then, there is an old joke about the temperence reformer who visits a small town, and rents a lecture hall. Finding out that the local saloon's sales have increased 25 percent in the last year, she harrangues the crowd about how the town is drinking 25 percent more alcohol than before. From the back of the hall, the saloon owner shouts, "No, Ma'am ... They're drinking 25 percent more water!"

In reply to your question, I would say that 30 percent is well above the threshold for adulteration. It the horse gets above 50 percent, then it would be horsemeat that has been adulterated with beef.

Madison Avenue would use the word "enriched", and charge extra for the horsemeat; Adulteration sounds too legalistic.

I do not know any foodies, but I know a few adulterers (even an adultress or two). If I run into one on my next trip to town, I'll ask for an "expert" opinion.

Roger, did you mean 'supplementing'? Caddle - baddle - saddle ?
Well, not quite (yet) in UK but if you're called Leonora Casement (? real name) perhaps anything goes. Yes, the 'pure Angus' is fine, but will Leonora allow the international-National identity?

Douglas, let's hope Leonora's wording was a nod and a wink to the
equine shenanigans.

Jerome,
I'm hoping that she's not a cat fanatic, hasn't a wolf dog, and hasn't married a Cambodian.

No, I don't think it's her real name. Have you ever met anyone called Leonora?

What you find in an old English stew
Is donkey, dog, horse, kangaroo,
Yes, all of the mammals
Including the camels
With bullfrogs and crocodiles too.

Jerome, I think it is well within the tradition of limericks. Indeed, some of them even end with an entire phrase repeated from an earlier line.

On the other hand, if you can think of another word that rhymes with 'national' and 'rational' ...

P.S. I too have wondered as to the significance of the name 'Leonora Casement'. The competition lady at the NS is actually Vicky Hutchings.

Douglas, you have one extra syllable in the second line of your limerick. To my ear at least.

Have you ever met anyone called Leonora? (John W.)

Yes, John, strangely enough I have. I was researching an article about lethal pine-cones, as one does, and for comparison purposes needed to know the weight of an average coconut so the lovely Leonora kindly put one on her scales for me in the grocer's shop she was then working in. This was on the S. Devon coast, but it turned out that by an amazing coincidence she hailed from the next village down the Wye in Herefordshire from the one I lived near for six golden youthful years.
Ahhh . . . but then ohhh . . . she had married a local Labour activist, so it was not to be. (Sob)

The coconut weighed about 2 pounds, by the way. You never know when that sort of information might come in useful.