The tropical and subtropical regions of the world are home to roughly 65% of the world population, the majority living in developing countries. In these regions, agriculture and livestock production are the most important economic sectors, significantly contributing to local food security. Improving animal production in the tropics is of the utmost relevance to address development issues. In such a context, intensive poultry production is one of the most efficient ways of meeting such challenges. Indeed, poultry production leads to high-valued protein products (meat and eggs) of high nutritional value cheaply, efficiently and without the need for large areas.

Heat stress in an important conditioning to tropical poultry production. The Naked Neck (Na) is the single dominant autosomal gene that reduces feathering in the neck region, thus improving heat dissipation. The Na gene has long been demonstrated to confer heat stress tolerance through the feather coverage reduction but also through some particular behavioural traits Generally, animals with the naked neck gene have higher growth rates and higher proportions of high-value carcass parts when compared to normal feathered animals particularly at high ambient temperatures, although contrary observations may also be found.

As we have recently reviewed, over recent years, microalgae such as Arthrospira platensis, (generally known as Spirulina) and Chlorella vulgaris are considered as an interesting alternative protein source for animal feeding. Furthermore, microalgae have a very high crude protein content (75% versus 45% in soybean meal), have interesting mineral, vitamin and antioxidant contents, and are a rich source of n3 LCPUFA (long-chain polyunsaturated fatty acids). Spirulina has been used in poultry production as both an ingredient and as a feed additive.

Nevertheless, a strategy combining chickens with different genetic backgrounds and fed a novel feedstuff such as spirulina has never been conducted. It will also be important and urgent, not just to study the use of alternative feedstuffs on the productive performance, but also to understand the nutritional and physiological implications of their use combined with heat stress. Finally, the way the project is designed will allow the introduction of a major component that is frequently understudied in projects related to alternative feedstuffs. This will bring a novel new approach that will be of key relevance to ascertain the sustainability of the use of such novel feeds.