I do the fruit exchange regularly. I noticed in the past 2 months truffles drop less. I have 3 Royal pigs and my truffles were not refilling as they used to. Plus Sir Pig drastically reduced his drop rate. Previously the norm, now the exception. So I started very low on truffles and had to buy the last ones after 2 days of harvesting only piggies. Lesson learned: keep truffles at over 80 at all times.