NUTRITION
Guinea pigs also have exacting nutritional requirements and develop taste preferences for familiar food. Guinea pigs lack the enzyme L-gulonolactone oxidase which is necessary for the synthesis of vitamin C in the liver. Therefore, they must receive vitamin C in their diet. The dietary requirement for vitamin C is about 20 mg/kg/day for a growing guinea pig and higher for pregnant or lactating females.
Commercial laboratory guinea pig feed is supplemented with vitamin C and it should be stored in a cool area under refrigeration. Guinea pig ration more than 90 days old should not be used unless a vitamin C supplement is also fed along with it.