Hi, my baby is 21 days old born premature at 35 weeks and 3 days via c- sec. He had respiratory distress on birth and was. Admitted in NICU for 4 days where. He was given APTAMIL formula milk via NG tube. Although his respiratory rate at the time of discharge was 70. He does not take feed properly.. So i generally switch between breast feeding and formula milk that, was given by hospital.. From last 2-3 days he is not taking feed properly.. Neither his formula nor breast milk.. Do i need to change his formula milk or continue with same?? Shall I switch to Nanpro 1 or Similic??