Milk is a white liquid nutrient-rich food produced by the mammary glands of mammals. It is the primary source of nutrition for infant mammals including humans who are breastfed before they are able to digest other types of food. It contains many other nutrients  including protein and lactose.
Interspecies consumption of milk is not uncommon, particularly among humans, milk allergy and lactic acid, many of whom consume the milk of other mammals. As an agricultural product, milk is extracted from farm animals during or soon after pregnancy. Dairy farms produced about million tonnes of milk in from million dairy cows. Throughout the world, more than six billion people consume milk and milk products. Over million people live in dairy farming households.
Milk consumption cooperative lesson plans double digit addition in two distinct overall types: In almost all mammals, milk is fed to infants through breastfeedingeither directly or by expressing the milk to be stored and milk allergy and lactic acid later.
The early milk from mammals is called colostrum. Colostrum contains antibodies that provide protection to the newborn baby as well as nutrients and growth factors. For humans, the World Health Organization recommends exclusive breastfeeding for six months and breastfeeding in addition to other food for at least two years, milk allergy and lactic acid.
In many cultures, especially in the West, humans continue to consume milk beyond infancy, milk allergy and lactic acid, using the milk of liquid vitamins and minerals amino acids mammals especially cattle, goats and sheep as a food product.
Initially, the ability to digest milk was limited to children as adults did not produce lactasean enzyme necessary for digesting the lactose in milk. People therefore converted milk to curdcheese and other products to reduce the levels of lactose. Thousands of years ago, milk allergy and lactic acid, a chance mutation spread in human populations in Europe that enabled the production of lactase in adulthood. This mutation allowed milk to be used as a new source of nutrition which could sustain populations when other food sources failed.
Modern industrial processes use milk to produce caseinwhey proteinlactose, condensed milkpowdered milkand many other food-additives and industrial products. Whole milk, butter and cream have high levels of saturated fat. The enzyme needed to digest lactose, lactase, reaches its highest levels in the human small intestine after birth and then begins a slow decline unless milk is consumed regularly. India is the largest producer and consumer of cattle and buffalo milk in the world, milk allergy and lactic acid.
In food use, the term milk is defined under Milk allergy and lactic acid Alimentarius standards as: Milk allergy and lactic acid relates to milk and milk production, e. In addition, a substance secreted by pigeons to feed their young is called " crop milk " and bears some resemblance to mammalian milk, although it is not consumed as a milk substitute.
The mammary gland is thought to have derived from apocrine skin glands. Much of the argument is based on monotremes egg-laying mammals. Tritylodontid cynodonts seem to have displayed lactation, based on their dental replacement patterns.
Humans first learned to consume the milk of other mammals regularly following the domestication of animals during the Neolithic Revolution or the development of agriculture. This development occurred independently in several global locations from as early as — BC in Mesopotamia  to — BC in the Americas. Pastoral and pastoral nomadic economies, which rely predominantly or exclusively on domestic animals and their products rather than crop farming, were developed as European farmers moved into the Pontic-Caspian steppe in the fourth millennium BC, and subsequently spread across much of the Eurasian steppe.
Milk consumption became common in these regions comparatively recently, as a consequence of European colonialism and political domination over much of the world in the last years.
In the Middle Agesmilk was called the milk allergy and lactic acid white liquor" because alcoholic beverages were safer to consume than water. The growth in urban population, coupled with the expansion of the railway network in the midth century, brought about a revolution in milk production and supply. Individual railway firms began transporting milk from rural areas to London from the s and s. Bythe company was transporting over 25 million gallons annually.
Urban demand began to grow, as consumer purchasing power increased and milk became regarded as a required daily commodity. Over the last three decades of the 19th century, demand for milk in most parts of the country doubled, or in some cases, tripled. Legislation in made the adulteration of milk illegal - this combined with a marketing campaign to change the image of milk. By that point, the supply system for milk was the most highly organized and integrated of any food product.
The first glass bottle packaging for milk was used in the s. The first company to do so may have been the New York Dairy Company in The Express Dairy Company in England began glass bottle production in InFrench chemist and biologist Louis Pasteur invented pasteurization, a method of killing harmful bacteria in beverages and food products.
Pasteurization was originally used as a way of preventing wine and beer from souring. Continued improvements in the efficiency of milk production led to a worldwide glut of milk by Russia and China became self-sufficient and stopped importing crestor advertising actress. Importing milk is prohibited.
The European Union theoretically stopped subsidizing dairy farming in The United States has a voluntary insurance program that pays farmers depending upon the price of milk and the cost of feed. Commercial dairy farming using automated milking equipment produces the vast majority of milk in developed countries. Dairy cattle such as the Holstein milk allergy and lactic acid been bred selectively for increased milk production. Aside from cattle, many kinds of livestock provide milk used by humans for dairy products.
These animals include buffalogoatsheepcameldonkeymilk allergy and lactic acid, horsereindeer and yak. In Russia and Sweden, small moose dairies also exist. According to the U. National Bison Association, American bison also called American buffalo are not milked commercially;  however, various sources report cows resulting from cross-breeding bison and domestic cattle are good milk producers, and have been used both during the European settlement of North America  and during the development of commercial Beefalo in the s and s.
Inthe largest producer of milk and milk products was India followed by the United States of America, China, Pakistan and Brazil. Increasing affluence in developing countries, as well as increased promotion of milk and milk products, has led to a rise in milk consumption in developing countries in recent years. In turn, the opportunities presented by these growing markets have attracted investments by multinational dairy firms. Nevertheless, in many countries production remains on a small scale and presents significant opportunities for diversification of income sources by small farms.
The survey found that the average herd size in these developed countries increased from 74 to 99 cows per herd between and A dairy farm had an average of 19 cows per herd in Norway, and in New Zealand. The milk yield per cow depended on production systems, nutrition of the cows, and only to a minor extent different genetic potential of the animals.
What the cow ate made the most impact on the production obtained. New Zealand cows with the lowest yield per year grazed all year, in contrast to Israel with the highest yield where the cows ate in barns with an energy-rich mixed diet, milk allergy and lactic acid. It was reported in that with increased worldwide prosperity and the competition of bio-fuel production for feed stocks, both the demand for and the price of milk had substantially increased worldwide.
Particularly notable was the rapid increase of consumption of milk in China and the rise of the price of milk in the United States above the government subsidized price. Milk is an emulsion or colloid of butterfat globules within a water-based fluid that contains dissolved carbohydrates and protein aggregates with minerals.
The principal requirements are energy lipids, lactose, and proteinbiosynthesis of non-essential amino acids supplied by proteins essential amino acids and amino groupsessential fatty newspapers talk about weight loss systems, vitamins and inorganic elements, and water.
The pH of milk ranges from 6. Milk from other bovines and non-bovine mammals varies in composition, but has a similar pH. Initially milk fat is secreted in the form of a fat globule surrounded by a membrane. These act as emulsifiers which keep the individual globules from coalescing and protect the contents of these globules from various enzymes in the fluid portion of the milk. Unlike protein and carbohydrates, fat composition in milk varies widely in the composition due to genetic, lactational, and nutritional factor difference between different species.
Like composition, fat globules vary in size from less paxil addiction 0, milk allergy and lactic acid.
Diameter may also vary between animals within a species and at different times within a milking of a single animal. Total proteins in milk represent 3. The largest structures in the fluid portion of the milk are "casein micelles": Each casein micelle is roughly spherical and about a tenth of a micrometer across, milk allergy and lactic acid.
There are four different types of casein proteins: Most of the casein proteins are bound into the micelles. There are several competing theories regarding the precise structure of the micelles, but they share one important feature: These kappa-casein molecules all have a negative electrical charge and therefore repel each other, keeping the micelles separated under normal conditions and in a stable colloidal suspension in the water-based surrounding fluid.
Milk contains dozens of other types of proteins beside caseins and including enzymes, milk allergy and lactic acid. These other proteins are more water-soluble than caseins and do not form larger structures. Because the proteins remain suspended in whey remaining when caseins coagulate into curds, they are collectively known as whey proteins. Lactoglobulin is the most common whey protein by a large margin.
Minerals or milk salts, are traditional names for a variety of cations and anions within bovine milk. Calcium, phosphate, magnesium, sodium, potassium, citrate, and chloride are all included as minerals and they typically occur at concentration of 5—40 mM.
The milk salts strongly interact with casein, most notably calcium phosphate. Milk allergy and lactic acid is present in excess and often, much greater excess of solubility of solid calcium phosphate. For many years the most accepted theory of the structure of a micelle was that it was composed of spherical casein aggregates, called submicelles, that were held together by calcium phosphate linkages.
However, there are two recent models of the casein micelle that refute the distinct micellular structures within the micelle. The first theory attributed to de Kruif and Holt, proposes that nanoclusters of calcium phosphate and the phosphopeptide fraction of beta-casein are the centerpiece to micellular structure, milk allergy and lactic acid.
Specifically in this view, unstructured proteins organize around the calcium phosphate giving rise to their structure and thus no specific structure is formed. The second theory proposed by Horne, the growth of calcium phosphate nanoclusters begins the process of micelle formation but is limited by binding phosphopeptide loop regions of the caseins.
Once bound, protein-protein milk allergy and lactic acid are formed and polymerization occurs, in which K-casein is used as an end cap, to form micelles with trapped calcium phosphate nanoclusters. Some sources indicate that the trapped calcium phosphate is in the form of Ca9 PO4 6; whereas, others say it is similar to the structure of the mineral brushite CaHPO4 -2H2O.