It's entirely up to you. We eat our older hens. No kids anymore, but when they were home, they knew where their food came from. When the boys were 10, 8 and 5, we got a single bottle calf from a neighbor that was going out of milking. This was the last calf born on their farm. The kids named him Butch "because we're gonna butcher him anyway, Mom". I think how the adults in the household handle the death of an animal (whether pets or livestock) greatly affects how the kids handle it. We were always matter of fact when it came to processing our animals. (We took the steers into town, we didn't butcher them ourselves). The same way when one got sick or injured and died. The kids handled it way better than I did at times.