Why was the act of feeding a black dog, as instructed by Sai, considered more spiritually significant than the advice Janakidas Baba gave Kashiram about feeding ants?

The premise of this question is incorrect based on the available information. The source texts do not contain any mention of feeding a black dog, nor any instruction from Sai Baba to do so. Therefore, no comparison can be made regarding its significance. The only related act described in Chapter 0 is Kashiram's practice of carrying powdered sugar to feed ants, which he did on the advice of a saint named Janakidas Baba. This practice was so dear to him that he fought robbers to protect his bundle of sugar. There is no account of Sai Baba giving instructions about a black dog.