Skinners Field & Trial Muesli Mix 15kgSkinners Field & Trial Muesli Mix. Field & Trial Muesli Mix is a complete working dog food based on a traditional mix of ingredients, specially developed and formulated to support dogs with a moderate to high activity level. The mix of whole wheat biscuits, cooked cereals and vegetables (maize, wheat flakes and peas) combined with beef based protein pellets and all the essential oils, vitamins and minerals that your dog needs, creates an interesting