As children, we learned where our food comes from, how it gets there and what it takes to supply a family of meat. Personally, all us kids had a job, the meat birds began on a "Clothes line" (not used for clothes), someone killed them, one of the bigger kids hung them, the next one took them down and dipped them, we younger ones plucked them, then they went into a wheel barrow and quickly taken into the house where our mothers would clean and package.
You have milk cows, that can be friends with, steers, you eat, leave them alone. Layer hens, you can be friends with, meaties, you cannot.
People need to teach their kids the value of life, that we all have a purpose and we thank them for giving us nutrition and handle them as humanely and respectfully as possible.
Unfortunately this is part of the process, perhaps not allowing them to see the head lopped off quite yet for the younger ones, but 8-12 they need to know that not everything lives happily ever after.
(My opinion only)