The objective of this experiment was to obtain an optimum combination between field grass. concentrate and Nutrient Rich Supplement (NRS) based on in vitro study using Hohenheim gas test. Theexperimental diets were: R1 (control diet = 70% field grass + 30% concentrate). R2 (70% field grass +25% concentrate + 5% NRS). https://parisnaturalfoodes.shop/product-category/men-50-multivitamins/