Effects of allicin on ascites syndrome traits and angiotensin II type 1 receptor gene expression in broilers reared in the Mexican highlands

Ascites syndrome (AS) is a deadly condition in fast-growing chickens, preceded by pulmonary arterial hypertension (PAH), where the angiotensin II type 1 receptor (ATR1) plays a role. We investigated whether allicin (ALLI), a garlic derivative, could (a) interact with broiler ATR1, (b) affect ascites-related traits [haematocrit content (Hct%), blood oxygen saturation (SaO₂), and the right-to-total ventricular weight ratio (RV:TV)], (c) modify ATR1 expression in the lung, heart, and liver, alongside ascites mortality and growth performance in Ross 308 broilers raised at high altitude and under cold temperatures promoting PAH/AS. Three groups (n = 70 each) were studied: 0-ALLI (untreated), 1-ALLI (allicin 1 mg/kg bodyweight/daily at 14-27 days of age by oral-oesophageal route), and 2.5-ALLI. After 3-6 weeks, Hct%, SaO₂, RV:TV ratios, and ATR1 expression in the lung, heart, and liver, were evaluated. Weekly productive performance and AS mortality were recorded. Molecular dockings and dynamic simulations predicted that ALLI might inhibit broiler ATR1 in a transitory manner. At 42 days of age, birds in the 2.5-ALLI group exhibited lower Hct% and lower RV:TV values, while ALLI marginally enhanced SaO₂. ATR1 expression in the 1-ALLI and 2.5-ALLI groups was higher (i.e. restored) in the lungs and heart, respectively, but not in the liver compared with the untreated group. Productive performance remained unaffected by ALLI, and 2.5-ALLI provided a protection of 4.3% against ascites mortality. In conclusion, 2.5-ALLI mitigated PAH/AS traits in the lungs and heart without compromising broiler productive performance. Further studies adjusting ALLI doses and combinations are warranted.RESEARCH HIGHLIGHTS Broilers bred at >2000 m OSL and <20°C were treated with 1 or 2.5 mg allicin per os.Allicin at 2.5 mg per os decreased haematocrit and right ventricular hypertrophy.Allicin treatments restored ATR1 expression in the heart and lungs.Productive performance of broilers was not affected by allicin treatments.Allicin is a promising candidate to enhance the quality of poultry production.