Evaluation of Growth, Carcass, Immune Response and Stress Parameters in Naked Neck Chicken and Their Normal Siblings under Tropical Winter and Summer Temperatures

The performance of naked neck and normal chicken was evaluated with respect to growth, carcass, immune, biochemical and stress parameters under winter and summer seasons to assess the suitability of naked neck birds under high temperatures in the global scenario of climate change. The growth performance was significantly (p≤0.05) higher in naked neck chicken in the summer season. The dressing percentage was significantly (p≤0.05) higher in naked neck birds in both winter and summer season because of reduced plumage. The thigh, giblet and feather proportion significantly (p≤0.05) varied between naked neck and normal chickens in summer season. The humeral immune response to sheep red blood cells (SRBC), Newcastle disease vaccine (NDV) and cutaneous basophil hypersensitivity (CBH) did not show any significant differences among the chicken groups. The protein and cholesterol concentration observed was within the normal ranges. The total cholesterol levels in plasma were significantly (p≤0.05) lower in naked neck birds in both the seasons. H:L ratio was significantly (p≤0.05) lower in summer season indicating less stress in naked neck chicken. Basophil and eosinophil concentration was significantly (p≤0.05) higher in normal chicken in summer. The lipid peroxidation was higher in full feathered birds under summer stress. The enzyme glutathione reductase (GR) levels were significantly higher during the summer and varied significantly (p≤0.05) between the normal and naked neck chicken in both seasons. The results indicated that the naked neck birds performed significantly better at high ambient temperatures with respect to growth, carcass and biochemical parameters. It was concluded that the ability of the naked neck chicken to adapt to high temperatures foresees a viable option for the biological mitigation of climate change. (