Overall skinners is not an amazing product, breeders tend to recommend brands such as this and ones like chudlys as it's is what has been used for a long time with working dogs and it is very affordable. However these products are on the lower end of the food quality scale, depending on which specific one you are using the quality varies however it does tend to be packed full of derivatives, cereals, grain and additives which some may think are suitable but rather they are not.
Cereal and grain (rice, barley, wheat. Oats) are used in dog door and cat food to make it more affordable, it is a bulking product, make more of the food at a cheaper price however cereals and grain are not biologically appropriate for these animals, often they have trouble breaking down this product, they suffer with allergic reactions and as it is packed full of these products it removes a lot of the meat and vegetables from the food therefor removing flavour, smell and nutrients. In simple terms dogs are omnivore so simply they should only really have meat, offal, bone, fruit and veg in the diet.. anything else is questionable
Regardless of the bread they always do better on a grain free food. It does tend to up slightly in price the higher quality you go but you do have to feed less of it so works out cheaper in the long run. Feeding a food which has a higher meat content (meat, not derivatives or extracts) often increases the dogs appetite meaning they will be more enclined to eat and will obtain more from their food.
Brands I would recommend trying would me
Raw diet (Natures menu, beyfit, nutriment)
Taste of the wild
For the medium quaility (better the skinners)
I would recommend orijen personally but obviously price is a factor
If you need advice with food Kennel Gate pet shop is really good for their advice, if you needed help in person and needed showing the foods.