How to Increase Livestock Affections
The easiest (and free) way is to talk to them every day. You can also purchase a brush from Saibara, and brush your barn animals every day. It is not too advisable to waste Harvest Spirit in taking care of animals. After all, Harvest Spirits will ship your animal product instantly without further processing them (to fetch even higher price). Also, given you talk and brush your livestock inside the barn, no time will be consumed anyway.