The study used a developer phase of Sentul chickens aged 18 weeks in 20 cages. This study used a completely randomized design (CRD) with five treatments consisting of R₀ (basal diet), R₁ (basal diet with Chitin 0.5%), R₂ (basal diet supplemented with 1.0% Chitin), R₃ (basal diet supplemented with Chitin 1.5%), and R₄ (basal diet supplemented with Chitin 2.0%). Each treatment was repeated four times with the observed variables were the number of red blood cells (RBC), blood haemoglobin levels, haematocrit levels and blood cholesterol. The results showed that the use of 0.5% Chitin feed supplement can meet the health requirements of blood parameters. The use of chitin supplement feeds improved the haematocrit and blood cholesterol parameters at the chitin level by 1.0%, while the optimal red blood cell count was 2.0% in Sentul chicken rations.