Small ruminants, such as sheep (Ovisaries) and goats (Capra hircus), contribute to approximately 475 million metric tons of carbon dioxide equivalent (MtCO₂e) greenhouse gas (GHG) emissions, accounting for approximately 6.5% of the global emissions in the agriculture sector. Crop residues, silage, grasses, hay, browse, plant leaves, shrubs, agro-industrial by-products, poultry litter, and other alternative feed sources are frequently utilized for small ruminant production. The use of these valuable alternative feeds can significantly improve animal productivity and reduce carbon footprints and GHG fluxes, making it both environmentally friendly and cost-effective. Additionally, these alternative feeds possess antioxidant, antimicrobial, and antiseptic properties that can enhance the quality of the meat and milk produced. By impacting the bacteria involved in ruminal biohydrogenation, alternative feeds can reduce methane emissions and contribute to a decrease in the carbon footprint. Overall, the use of alternative feed sources for small ruminants generally improves their apparent nutrient digestibility and productivity, and has an impact on the production of greenhouse gases, especially methane. Finally, this review recommends evaluating the economic analysis of reducing methane emissions in small ruminants by utilizing different feed sources and feeding techniques.

Sustainability is a major challenge for global food systems, particularly in the context of food loss and waste. Approximately one-third of food produced worldwide (1.3 billion tons annually) is lost or wasted, contributing to 8–10% of global greenhouse gas emissions, with a large share occurring during post-harvest handling and food processing. These stages generate by-products such as shells, skins, pulp, stems, and seeds, which can account for 30–50% of raw materials. Although often discarded, these residues are rich in valuable bioactive compounds, including phenolics, peptides, carotenoids, fibers, secondary metabolites, minerals, amino acids, and vitamins. This review emphasizes the valorization of agrifood by-products as a pathway toward sustainability and the achievement of the Sustainable Development Goals (SDGs). It encompasses extraction methods, characterization, and potential uses of such active compounds in the food, pharmaceutical, packaging, and cosmetic sectors. Moreover, it examines the interaction between valuing agrifood by-products and key SDGs like eliminating hunger (SDG 2), ensuring good health and well-being (SDG 3), promoting affordable and clean energy (SDG 7), promoting economic growth and decent work (SDG 8), ensuring responsible consumption and production (SDG 12), and tackling climate action (SDG 13). These approaches have high potential to improve food security and economic sustainability of the world’s food systems.

The aim of this experiment was to study the effect of total replacement of oat hay by rosemary distillation residues (RR) on growth, carcass characteristics and meat quality of Barbarine lambs. A total of 21 lambs were divided into three groups. The control group (C) was offered 600 g of oat hay; the RR87 and RR60 groups received 600 g of pellets containing 87% and 60% of RR, respectively. The CP content was 9% and 14% for RR87 and RR60, respectively. All animals were supplemented by 600 g of concentrate. After 77 days of fattening, lambs were slaughtered. The DM and CP intakes were significantly increased with RR diets. The average daily gain was higher (P<0.001), while the feed conversion rate was lower for RR60 and RR87 than C group. The dressing percentage was similar for all groups. The tissular (muscle, fat and bone) and the regional (leg, shoulder, etc.) carcass composition did not differ among groups. The bony organs and gut weights were similar among groups, while functional ones (skin, liver, kidney and testicles) were significantly heavier for both RR groups than control. The ultimate pH, water cooking loss and color variables were similar among groups and the chemical composition (protein, fat, myoglobin, collagen and iron) did not differ also among groups. These results revealed the opportunity of RR use in fattening lambs without adverse effects on carcass and meat characteristics. Moreover, 9% CP in RR pellets are enough given the same growth performance recorded as that of RR with 14% CP.