I don’t really see how it’s any more cruel than eating lamb. And lamb is delicious.
“Lamb” is usually a misnomer for mutton.
This might be one of the things that the Tories are enthusiastically trying to change post-Brexit, but EU regulations state that something can only be labelled "lamb" if the animal was slaughtered before the age of 12 months.
Lamb , and, well, all sheep products are generally a bit less cruel than other animal products overall because it is quite a bit more difficult to factory farm sheep like you can with pigs, cows and chickens.