Production and Utilization of Milk

Abstract

Milk is a fluid secreted by the female of all mammalian species, of which there are more than 4,000, for the primary function of meeting the complete nutritional requirements of the neonate of the species. In addition, milk serves several physiological functions for the neonate. Most of the non-nutritional functions of milk are served by proteins and peptides which include immunoglobulins, enzymes and enzyme inhibitors, binding or carrier proteins, growth factors and antibacterial agents. Because the nutritional and physiological requirements of each species are more or less unique, the composition of milk shows very marked inter-species differences. Of the more than 4,000 species of mammal, the milks of only ~180 have been analysed and of these, the data for only about 50 species are considered to be reliable (sufficient number of samples, representative sampling, adequate coverage of the lactation period). Not surprisingly, the milk of the principal dairying species, i.e., cow, goat, sheep and buffalo, and the human are among those that are well characterized. The gross composition of milks from selected species are summarized in Table 1.1; very extensive data on the composition of bovine and human milk are contained in Jensen (1995).