Hearts, and what ten hearts really does
Every animal is scored once overnight. Petting it is worth 5, and feeding it is worth 5 plus a bonus based on the food. An ordinary day of care is therefore +10. Missing care lowers the score. An animal that was not petted, not fed and left outside loses 15 in one night, so a missed day costs more than a good day gains.
Better food raises hearts faster, though the gain has a ceiling. A one-star cooked dish hand-fed to an animal is worth 10 heart points, the same as ultimate feed. Each additional star adds one point, making a five-star dish worth 14. Plain hay or seed is worth 5, so the dish gives nearly three times as much. Compared with ultimate feed, the difference is only 1.4×. Save expensive dishes for the last heart or two.
At ten hearts, the ordinary product stops completely and the animal produces only the golden version. You collect fewer items, but their daily value rises. A ten-heart hen is worth 66g a day, compared with 46g at nine hearts. This is the largest increase in value the animal makes. The table above shows the exact figures for every species.