We feed our pet animals more like humans than the animals they descend from. While the ancestors of our cats and dogs were mainly eating prey animals, nowadays a label of pet food looks more like a human dinner. How did that happen?
Firstly, most cats and dogs are raised in a limited living space, either completely indoors, or partly outside. Especially in densely populated areas they are kept with restricted freedom to move around the neighbourhood and surroundings. These restrictions are needed, because it is absolutely unacceptable for dogs to hunt down a neighbour’s rabbit or chicken, or for cats to catch your daughter’s hamster or beloved songbird! This limitation of natural behaviour and fulfilling nutritional requirements of the animal, gives pet owners a big responsibility to provide pet animals with a complete diet to support all body functions.
Secondly, not only are the animal’s requirements important in pet food, but also the convenience for the owner is very important, if not sometimes even more important! This relates to the digestibility and therefore excretion by the animal, but also to the quality and conservation of the food, the smell and looks of it and of course the price.
With much known about feeding monogastric animals (poultry and swine) and more research being done on nutrition and requirements of pet animals, pet food producers try to optimize their formulations. To be able to optimize the price of pet food, many use meat based byproducts and vegetable sources as the main ingredients. These formulations then need to be supplemented to optimize nutrient availability to fulfill all nutrient requirements and improve palatability, conservation and appearance.
For development, growth and maintaining health, mineral supplementation is essential in all phases of life. Compared to most monogastric livestock pet animals reach (much) higher ages, go through different phases of life and therefore also have different nutrient requirements. Finally, the huge variation in breeds and no selection on feed efficiency and growth performance traits, results in big variety between individual animals and breeds. Fulfilling nutrient requirements of pet animals in general and mineral requirements in particular is therefore challenging, but essential to maintain overall health and strength.
Essential minerals which are often supplemented are: zinc, copper, manganese and iron.
Zinc is a very essential mineral to maintain healthy skin, hair and nails. Next to that it is a critical element for many immunological processes to support general health and finally it is involved in the carbohydrate metabolism and reproduction.
Copper is involved in many processes in the body, with the main ones being the development of bone, connective tissue and collagen, the formation of hemoglobin and acting against free radicals in the body (anti-oxidant). It also aids the absorption of iron and the development of hair pigment.
Manganese is important for the proper function of many proteins and carbohydrates, fertility, growth and development, as it is necessary for the formation of bone and joint cartilage and neurological function.
Iron in combination with proteins and copper forms hemoglobin, essential for oxygen supply. Iron is needed continuously to provide hemoglobin for newly produced red blood cells. Low levels of available iron will lead to the development of anemia.
In nature cats and dogs get the necessary minerals mainly by eating organ meat from prey animals. Mainly liver is rich in minerals as it is important for distribution and storage of many nutrients in all animals. However organ meat is not always available, allowed or consistent in quality for pet food producers to use as the main or only source of minerals in their feed.