New Zealand lamb has more grass in their diet so I guess less methane produced and better for the environment even with transportation to uk.
Just to reiterate, vast majority of sheep eat grass. Not corn, not root crops, just grass with occasional tiny quantities of mineral supplements. No different to what the sheep in New Zealand eat! No magical difference between NZ and UK - both have mild, moist climates well-suited to pastoral agriculture, with extensive upland regions. As mentioned earlier, sheep farming is dramatically less intensive than something like dairy. And sheep produce less methane than cows, being very significantly smaller.
Omnivorous vs vegetarian diet not focus of thread, so don't want to push it and derail other, more useful conversations, but suggest we be skeptical of what we read. Many of us here naturally curious & questioning individuals - better we not suspend that instinct just because subject is meat / lamb.
Again, have no personal stake in this (other than background as farmer's son in Wales) but think it very odd that such low-intensity farming would be singled out. Anyway, no offence intended to anybody here, will let it drop now.