Standardized ileal digestible lysine and valine-to-lysine requirements for optimal performance of 4 to 9-week-old Piétrain cross piglets

•SID Lys requirements of 4 to 9-week-old piglets are estimated to be equal or greater than 11.4 g/kg (1.14%).•SID Val:Lys requirement was found to be between 68 and 74% for optimal growth and feed intake.•Balances between amino acids affect feed intake and growth of piglets.