The grim reaper keeps showing up to kill all of my farm animals

@mimistar794 I find that the Animal Aging setting in game options is "wonky" I use a mod by Little Ms Sam called "RBF - Disable Cottage Living Animal Aging Fix". It prevents newly acquired animals from cottage living and the mini sheep and goats from Horse ranch from aging. Existing in-game animals will continue to age until Grim shows up or you sell them, which ever comes first.

Note - this includes preventing chicks from becoming chickens, so just buy roosters and hens