Guinea pigs need a steady supply of vitamin C in their diet, since unlike most mammals they cannot make their own - which is why a guinea-pig-specific food fortifying it directly matters more than it would for, say, a hamster mix. Mr Johnson's Supreme recipe is built with that in mind.

It combines concentrate pellets (barley, wheatfeed, peas, limestone, soya, molasses and a vitamin and mineral supplement including vitamin C) with flaked peas, flaked barley, flaked maize, locust bean extrusions, flaked soya beans, dried carrot, grass and alfalfa, plus a Verm-X herb blend included for digestive health. Protein comes out at 17%, crude fibre at 9%, oils and fats at 4% and crude ash at 3%. Mr Johnson's own feeding guide gives roughly 25-35g a day for an adult guinea pig, 35-45g for a growing one and 40-50g for a lactating sow.

• Concentrate pellets plus flaked peas, barley, maize and soya
• Protein 17%, crude fibre 9%, oils and fats 4%, crude ash 3%
• Fortified with added vitamin C
• Includes grass, alfalfa and dried carrot
• Verm-X herb blend included
• Manufacturer's guide: roughly 25-35g/day adult, 35-45g/day growing, 40-50g/day lactating
• 15kg bag

On what's missing. No specific vitamin C figure in mg/kg is given on this card, only that it is included in the vitamin and mineral supplement, so if a vet has specified an exact vitamin C intake for your guinea pig, this card cannot confirm the amount.

Who it's for: guinea pig owners who want a fortified, varied complementary food with a manufacturer feeding guide already worked out by life stage.