Effects of alternative feed ingredients on red meat quality: a review of algae, insects, agro-industrial by-products and former food products

Following the promotion of animal welfare awareness, modern meat production should be applied ethically and sustainably. Alternative circular feeds such as algae, insects, agro-industrial by-products (AIBPs) and former food products (FFPs) play a key role to re-define the current meat production system. This review highlights the effects of feed ingredients mentioned above on red meat quality, from a blue-bio/circular economy point of view. The results show that when algae are added in adequate amounts, they can improve nutritional and sensory quality of meat. Insects, and AIBPs, can affect meat quality mainly in terms of selected components like fat content and quality, while the effects of FFPs as feed ingredients on meat quality are still limited. These alternative feedingstuffs are regarded as interesting protein/energy sources for animal diets and are expected to be increasingly used globally as a replacement for conventional feedstuffs. The inclusion level of insects, AIBPs and FFPs is often higher than that of algae, because algae are considered more as feed supplements instead of ingredients that mainly provide macronutrients to the animals. However, more research is needed for a comprehensive evaluation of these materials, especially in terms of: (i) feed formulation and processing methods (inclusion level of such materials and technology used for feed production); (ii) their potential impacts on animal growth and health status and on environmental footprint; (iii) carcass quality; and (iv) final meat product quality, safety and wholesomeness.