Influence of dietary inclusion of Spirulina on growth, carcass, and meat traits of naked neck and fully feathered broilers under heat stress

In tropical and subtropical regions, poultry production is a viable solution, although it faces two major challenges: heat stress (HS) and access to conventional feedstuffs. Poultry strains that are more adapted to HS, such as the Naked Neck gene, and alternative feedstuffs such as Spirulina are crucial to address these limitations. This study evaluated the effect of 15 % Spirulina ( Limnospira platensis ) in the diet on growth performance, carcass traits, and meat quality of Fully Feathered (FF) and Naked Neck (NN) slow-growth broilers under HS conditions (30 °C). Forty male broilers (20 FF, 20 NN) were individually allocated into four groups ( n = 10 ) for 84 days, fed ad libitum a control diet (C) or a 15 % Spirulina (SP) diet. The NN birds have a ∼ 13 % higher final body weight (BW) compared to FF birds ( p < 0.05). Overall, The SP diet negatively affected final BW (− 295,5 g), average daily gain (−4 g/d) and feed conversion ratio (+ 0.16) ( p < 0.05). SP-fed animals had increased mean viscosity of duodenum plus jejunum contents (10.43 vs. 4.54 cP; p < 0.05). Breast meat from SP broilers had higher values for yellowness (b*) (p < 0.0001), thawing loss (p < 0.05), and total carotenoids (p < 0.0001) when compared to controls. Strain and diet influenced fatty acid profile, resulting in changes in breast meat total saturated fatty acids, polyunsaturated fatty acids, and nutritional ratio. Despite lower performance with SP diet, NN broilers maintained superior heat tolerance and productivity. This study shows the potential of alternative feedstuffs and genetic traits to improve poultry production in challenging climates. • Spirulina inclusion (15 %) influenced growth performance under heat stress. • Naked Neck broilers showed greater heat tolerance than Fully Feathered animals. • Spirulina may support poultry resilience in tropical climates.