Dairy farming


Dairy farming is a class of agriculture for the long-term production of milk, which is processed for the eventual sale of a dairy product. Dairy farming has a history that goes back to the early Neolithic era, around the seventh millennium BC, in many regions of Europe and Africa. Before the 20th century, milking was done by hand on small farms. Beginning in the early 20th century, milking was done in large scale dairy farms with innovations including rotary parlors, the milking pipeline, and automatic milking systems that were commercially developed in the early 1990s.
Milk preservation methods have improved starting with the arrival of refrigeration technology in the late 19th century, which included direct expansion refrigeration and the plate heat exchanger. These cooling methods allowed dairy farms to preserve milk by reducing spoiling due to bacterial growth and humidity.
Worldwide, leading dairy industries in many countries including India, the United States, China, and New Zealand serve as important producers, exporters, and importers of milk. Since the late 20th century, there has generally been an increase in total milk production worldwide, with around 827,884,000 tonnes of milk being produced in 2017 according to the FAO.
There has been substantial concern over the amount of waste output created by dairy industries, seen through manure disposal and air pollution caused by methane gas. The industry's role in agricultural greenhouse gas emissions has also been noted to implicate environmental consequences. Various measures have been put in place in order to control the amount of phosphorus excreted by dairy livestock. The usage of rBST has also been controversial. Dairy farming in general has been criticized by animal welfare activists due to the health issues imposed upon dairy cows through intensive animal farming.

Common types

Although any mammal can produce milk, commercial dairy farms are typically one-species enterprises. In developed countries, dairy farms typically consist of high producing dairy cows. Other species used in commercial dairy farming include goats, sheep, water buffaloes, and camels. In Italy, donkey dairies are growing in popularity to produce an alternative milk source for human infants.

History

While cattle were domesticated as early as 12,000 years ago as a food source and as beasts of burden, the earliest evidence of using domesticated cows for dairy production is from the seventh millennium BC – the early Neolithic era – in northwestern Anatolia. Dairy farming developed elsewhere in the world in subsequent centuries: the sixth millennium BC in eastern Europe, the fifth millennium BC in Africa, and the fourth millennium BC in Britain and Northern Europe.
In the last century or so larger farms specialising in dairy alone have emerged. Large scale dairy farming is only viable where either a large amount of milk is required for production of more durable dairy products such as cheese, butter, etc. or there is a substantial market of people with money to buy milk, but no cows of their own. In the 1800s, economist Johann Heinrich von Thünen argued that there was about a 100-mile radius surrounding a city where such fresh milk supply was economically viable.

Hand milking

Centralized dairy farming as we understand it primarily developed around villages and cities, where residents were unable to have cows of their own due to a lack of grazing land. Near the town, farmers could make some extra money on the side by having additional animals and selling the milk in town. The dairy farmers would fill barrels with milk in the morning and bring it to market on a wagon. Until the late 19th century, the milking of the cow was done by hand. In the United States, several large dairy operations existed in some northeastern states and in the west, that involved as many as several hundred cows, but an individual milker could not be expected to milk more than a dozen cows a day. Smaller operations predominated.
For most herds, milking took place indoors twice a day, in a barn with the cattle tied by the neck with ropes or held in place by stanchions. Feeding could occur simultaneously with milking in the barn, although most dairy cattle were pastured during the day between milkings. Such examples of this method of dairy farming are difficult to locate, but some are preserved as a historic site for a glimpse into the days gone by. One such instance that is open for this is at Point Reyes National Seashore.
Dairy farming has been part of agriculture for thousands of years. Historically it has been one part of small, diverse farms. In the last century or so larger farms concentrating on dairy production emerged. Large scale dairy farming is only viable where either a large amount of milk is required for production of more durable dairy products such as cheese, butter, etc. or there is a substantial market of people with cash to buy milk, but no cows of their own. Dairy farms were the best way to meet demand.

Vacuum bucket milking

The first milking machines were an extension of the traditional milking pail. The early milker device fit on top of a regular milk pail and sat on the floor under the cow. Following each cow being milked, the bucket would be dumped into a holding tank. These were introduced in the early 20th century.
This developed into the Surge hanging milker. Prior to milking a cow, a large wide leather strap called a surcingle was put around the cow, across the cow's lower back. The milker device and collection tank hung underneath the cow from the strap. This innovation allowed the cow to move around naturally during the milking process rather than having to stand perfectly still over a bucket on the floor.

Milking pipeline

The next innovation in automatic milking was the milk pipeline, introduced in the late 20th century. This uses a permanent milk-return pipe and a second vacuum pipe that encircles the barn or milking parlor above the rows of cows, with quick-seal entry ports above each cow. By eliminating the need for the
milk container, the milking device shrank in size and weight to the point where it could hang under the cow, held up only by the sucking force of the milker nipples on the cow's udder. The milk is pulled up into the milk-return pipe by the vacuum system, and then flows by gravity to the milkhouse vacuum-breaker that puts the milk in the storage tank. The pipeline system greatly reduced the physical labor of milking since the farmer no longer needed to carry around huge heavy buckets of milk from each cow.
The pipeline allowed barn length to keep increasing and expanding, but after a point farmers started to milk the cows in large groups, filling the barn with one-half to one-third of the herd, milking the animals, and then emptying and refilling the barn. As herd sizes continued to increase, this evolved into the more efficient milking parlor.

Milking parlors

Innovation in milking focused on mechanizing the milking parlor to maximize the number of cows per operator which streamlined the milking process to permit cows to be milked as if on an assembly line, and to reduce physical stresses on the farmer by putting the cows on a platform slightly above the person milking the cows to eliminate having to constantly bend over. Many older and smaller farms still have tie-stall or stanchion barns, but worldwide a majority of commercial farms have parlors.

Herringbone and parallel parlors

In herringbone and parallel parlors, the milker generally milks one row at a time. The milker moves a row of cows from the holding yard into the milking parlor, and milks each cow in that row. Once all of the milking machines have been removed from the milked row, the milker releases the cows to their feed. A new group of cows is then loaded into the now vacant side and the process repeats until all cows are milked. Depending on the size of the milking parlor, which normally is the bottleneck, these rows of cows can range from four to sixty at a time. The benefits of a herringbone parlour are easy maintenance, durability, stability, and improved safety for animals and humans when compared to tie stall. The first herringbone shed is thought to have been built in 1952 by a Gordonton farmer.

Rotary parlors

In rotary parlors, the cows are loaded one at a time onto the parlor as it rotates in a circle. One milker stands near the entry to the parlor and pre-dips the teats on the udder to help prevent bacteria from entering. The next milker puts the machine on the cow to begin milking. By the time the platform has completed almost a full rotation, the cow is done milking and the unit will come off automatically. The last milker will post-dip her teats to protect them before entering back into the pen. Once this process is done, the cow will back out of the parlor and return to the barn. Rotary cowsheds, as they are called in New Zealand, started in the 1980s but are expensive compared to Herringbone cowshed – the older New Zealand norm.

Automatic milker take-off

It can be harmful to an animal for it to be over-milked past the point where the udder has stopped releasing milk. Consequently, the milking process involves not just applying the milker, but also monitoring the process to determine when the animal has been milked out and the milker should be removed. While parlor operations allowed a farmer to milk many more animals much more quickly, it also increased the number of animals to be monitored simultaneously by the farmer. The automatic take-off system was developed to remove the milker from the cow when the milk flow reaches a preset level, relieving the farmer of the duties of carefully watching over 20 or more animals being milked at the same time.

Fully automated robotic milking

In the 1980s and 1990s, robotic milking systems were developed and introduced. Thousands of these systems are now in routine operation. In these systems the cow has a high degree of autonomy to choose her time of milking freely during the day. These systems are generally limited to intensively managed systems although research continues to match them to the requirements of grazing cattle and to develop sensors to detect animal health and fertility automatically. Every time the cow enters the milking unit she is fed concentrates and her collar is scanned to record production data.