Physiological profiling and breed suitability modeling of slow-growing Thai native chickens: comparative insights with fast-growing broilers for sustainable poultry production

Indigenous Thai chickens, represented by the Maehongson (MHS) and Praduhangdum (PHD) breeds, are valued for adaptability, immune competence, and meat quality, but their slower growth limits adoption compared with broilers. To evaluate performance and resilience, growth traits, hematological and biochemical parameters were assessed, and a breed suitability index (BSI) was developed. A total of 450 mixed-sex birds (150 per breed) were raised under identical conditions, with blood sampling from 20 birds per breed. Analyses included correlations, PCA, and regression modelling, with standardised values synthesised into the BSI. Broilers grew fastest (ADG: 34.2 g/day; FCR: 1.37) but showed reduced RBC and haematocrit (1.93 × 106/mm³; 26.9%, p < 0.001), suggesting lower stress resilience. MHS had slower growth (947.9 g; ADG: 8.2 g/day) but higher RBC, haematocrit, eosinophils, and monocytes, reflecting stronger immune traits. PHD grew larger (1,999.6 g at 16 weeks; ADG: 17.5 g/day) with favourable serum profiles, including albumin (2.04 g/dL) and cholesterol (131.5 mg/dL). Breed-mean correlations (albumin-cholesterol r = 0.99) were stronger than individual-level correlations with ADG. PCA distinguished broilers (low RBC/Hb, high WBC/creatinine), PHD (high albumin/basophils), and MHS (high eosinophils/monocytes/UA). No single variable significantly predicted ADG. BSI ranked PHD highest (0.827), followed by MHS (0.614) and broilers (0.561), with strong ranking agreement (Kendall’s τ = 0.953). Results highlight trade-offs between rapid growth and physiological robustness. PHD shows potential for semi-intensive systems, while MHS may suit free-range or organic production. BSI offers a practical framework for sustainable breed selection in tropical poultry systems.