I think you have misunderstood me. The parent said that in poorer countries they may have to kill sheep when they are young if there is not enough grass to feed

I think you have misunderstood me. The parent said that in poorer countries they may have to kill sheep when they are young if there is not enough grass to feed them on in the winter. But we do not have the problem of a lack of animal food in the USA. We eat young sheep ("lamb") simply because they are considered to taste better. It is not due to material lack of animal feed.