Milk provides the essential energy, protein, lactose, vitamins, and minerals that young animals need for rapid growth and development.

Young animals, whether they are kittens, puppies, foals, or calves, are designed to grow rapidly. This growth covers not just their bones and muscles but also their brain, nervous system, digestive system, and immune system. 

To help support this growth (in addition to their daily energy needs), young animals need a diet high in energy, fat, and protein, with the right balance of vitamins and minerals.  

Until young animals begin eating solid food their diet consists entirely of their mother's milk (or a milk replacement formula). Each type of animal has a different milk composition (that is, the percentages of fat, protein and lactose) in order to best suit the growth needs of their young.