I maybe don't understand what 'rose veal' is.
Here's what I thought it is.
When veal had a bad name, calves were incarcerated in crates so that the blood stayed pale and the meat also stayed very pale, almost white. They were killed at about 6 months old, I think. They would never have seen the sun, never have run and skipped, never have eaten grass.
Back in the 70s, it was discovered that the meat would still be very pale, although not quite so white, if the calves were kept in reduced daylight, in strawed yards in wooden barns. No grass and no sunlight, but they could be reared in groups, could play and nibble straw.
. (The barns had to be wooden, not metal, to prevent them getting any iron, which would have coloured the blood.)
In the 80s, calf crates were outlawed in England. (I don't know if it was the whole of the UK or just England, but I do know they were outlawed in England.) At this point, many people began to eat veal again, provided it was English (ie., reared in strawed yards in groups, not in solitary confinement crates.)
More recently, people have been talking about rose veal. I had understood this to be very young animals still, not more than 8 month-ish, but which had been allowed to be outside and on grass. Hence more iron in the blood, more colour in the meat, 'rose' rather than very pale or white.
The Jersey dairy farm my Hillie came from (and sokel's Jersey bull calves too) rear and slaughter their own bull calves at about 18 months. It is beef, not veal, and it is dark and full of flavour. But there isn't much meat on an animal, and the butchering costs are more-or-less the same as for a more meaty beast, so for most folks there isn't enough profit in rearing the Jersey bull calf. Wheelbirks use their own beef in their cafe, and sell it from the farm, so manage to make it pay.
In England, the beef in the supermarket, unless it states otherwise, is likely to be predominantly continental breed, often Limousin beasts, generally 16-22 months old. The same will be true of a lot of butchers' beef, too. Any beef from a more native type, matured for up to 30 months (legal maximum since BSE - which is a shame, as some breeds benefit from a further 6-12 months), may appear in the regular beef packs but is more likely these days to be marked as Hereford, Aberdeen Angus, Shorthorn, [Ruby Red] Devon, Galloway or whatever, and be slightly more expensive. Not much of it will be 30 months old, but the majority will be nearer to 26 months than 20, as it takes these animals that bit longer to reach maturity.
We get our early lambs away at 14-16 weeks old, typically, weighing 37-39k kgs. They'll kill out at 18-19 kgs. The continental market will buy lambs much smaller than the home market wants, down to 14kgs deadweight and less. There is also a very specific continental market for 'milk lamb', which is the hill sheep's lambs, straight off their mothers (ie., not weaned), straight off the hill, typically about 4 months old and not, to a home market eye, anywhere near finished. I guess this is the ovine equivalent of 'veal'.
Generally I prefer my meat well matured (and well hung after butchering too) - deep dark red, full of flavour.
But I can see the appeal of the occasional, more subtley flavoured and generally mouth-wateringly tender, meat from a much younger animal, not hung for long. Much paler, succulent and sweet. I had 30-month Castlemilk Moorit chops tonight, and I challenge anyone to produce a lamb chop with more flavour. But I do still enjoy the occasional meal of young Charollais lamb - nothing like the depth of flavour, but tender, moist, sweet and succulent.
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