Koi fish, a rapidly growing ornamental species in Indonesia, are highly susceptible to koi herpes virus (KHV), which affects fish production. A 2013 screening based on MHC alleles identified F0 parents with positive MHC characteristics, leading to the development of MHC F1 koi generations. This study aimed to evaluate the growth and disease resistance of MHC F1 koi seeds, specifically to KHV, with recombinant growth hormone (rGH) supplementation in their feed. Results showed that rGH significantly improved growth rates and survival, with the highest survival in MHC seeds vaccinated against KHV (80%) and the lowest in non-MHC seeds without vaccination (35.56%). The study suggests that rGH supplementation enhances growth, and MHC-based KHV resistance genes improve disease resilience in koi fish.