Grain Free Adult Dog Food - Venison with Sweet Potato & MulberryKibble UK Grain Free Dog Food Why Venison? Venison is protein rich and nutritionally wholesome. It is a good source of iron and B vitamins including B6 and B12. Why Mulberry? Mulberry is rich in iron and vitamin C, an antioxidant, which can help support the immune system. Minimum 26% Freshly Prepared Venison: Responsibly sourced and highly digestible protein source. 50% Total Venison & Salmon: Rich in amino acids, vitamins & minerals, venison and