Important quantities of crop residues and by-products are yearly available in North African countries. This paper presents the screening of the most important by-products in Tunisia, their nutritional characteristics and the appropriate strategies to use most of them in order to improve ruminants feeding systems. One or several by-products are specifie of each region of the country but most of them are localized in the northern region. Some of the agricultural wastes are available in important quantities but are of nutritionally poor or moderate qualities (straw, olive wastes, poultry litter, etc), while others are produced in limited amounts but are of very interesting feeding values (sugar beet pulp, brewers grain, date residue, etc). The main applied strategies to valorize Tunisian agricultural by-products consist in ammoniation of cereal straws along with supplementation with multinutriment blocks and formulation of balanced diets based totally or partially on them. These alternatives are crucial in the improvement of feeding values of studied diets and animal performances essentially by improving micro-bial activity in the rumen. In Tunisia such solution could be applied both in extensive and moderate animal production systems