Background: Pulmonary hypertension syndrome (PHS) in broiler chickens is exacerbated by cold stress, leading to physiological responses that can adversely affect cardiac health. This study investigates the relationship between heart telomere length and lipid peroxidation in chickens experiencing PHS due to cold stress.
Materials and Methods: A total of 31-day-old male Ross 308 broiler chicks were divided into control and cold-stress (PHS) groups, with the latter exposed to decreasing temperatures to induce PHS. At 21 and 42 days of age, we assessed the right ventricular to total ventricular (RV:TV) ratio, relative heart telomere length through real-time quantitative PCR, and serum malondialdehyde (MDA) levels as a marker of lipid peroxidation.
Results: The RV:TV ratio was significantly higher in the PHS group at both 21 days and 42 days compared to controls. Relative telomere length was significantly reduced in the PHS group at 42 days (P<0.05), while MDA levels were elevated at this age (P<0.05). A negative correlation between telomere length and MDA levels was observed at 42 days (P<0.05). 
Conclusion: Cold stress-induced PHS in broiler chickens leads to increased oxidative stress, as evidenced by elevated MDA levels and reduced telomere length. The findings suggest that oxidative damage may accelerate telomere attrition, linking environmental stressors to cardiac dysfunction in poultry.