Cows are milked twice per day on most farms. However, 10% increased milk production can be obtained by milking the cows 3 times per day, and many dairy farms are beginning to do so. Some operations even milk a portion of their cows 4 times per day. Cows housed in tiestall barns are often milked in their stalls. A number of dairy farms, primarily those whose owners are members of religious denominations that do not utilize electricity, still milk cows by hand rather than with milking equipment. These are not common and usually involve only a few cows. The milk from such operations does not enter the fresh milk market and is utilized only for manufacturing purposes. Most cows milked in tiestall barns are either milked with bucket milkers or pipeline milking systems. Milking cows in tiestall barns is extremely labor intensive and requires much stooping and bending. The desire to reduce this type of labor has led to many types of milking parlor designs, in which the milker need not bend to be at the level of the cows udder.
Some cows in the Midwest and Northeast are milked in Tie Stall Barns.
- Hand Milking (Amish)
- Bucket Milkers
Walk-through or step-up parlors are often installed or retrofitted into existing tiestall barns as a cost effective way of alleviating the demands of the milking chore. In these parlors cows enter from the rear, step up onto an elevated platform for milking, and then exit forward through a headgate. Walk through parlors are inexpensive, but labor demands are still relatively high.
One of the most popular types of parlors is the herringbone,
so named because the cows enter and stand next to each other, but face away
from the operator's pit at an angle. Milkers
attach the milking clusters to the teats from
the side of the cow, and to have better visual contact with the cow's udder
while she is being milked. It is usually easier to keep the milker positioned
properly beneath the cow's udder.
Parallel parlors are similar to the herringbone parlors except that cows stand perpendicular to the operator pit and the cows are milked from the rear, between the cow's hind legs. Advantages are that the cows stand closer together so the worker has to walk less between cows that are being milked. Disadvantages are that the cow's tail is often in the way and it may be a long reach for some milkers to reach the cow's front teats.
Rotary parlors are gaining in popularity. Some older styles of rotary parlors were not very efficient or dependable. New ones, however, have proven to be a viable alternative for large dairy farms. With the rotary parlor, the platform on which the cows stand moves around, while the cleaners and milkers stand in one location. Milking cows is still a demanding task, however, because the cows come by so quickly that each task must be performed in about 10 to 12 seconds with no break between cows.
No matter what kind of parlor is used, there are some key components of milking procedures that are followed in each. Namely, the cow's teats must be thoroughly cleaned and dried, the milking equipment must be working properly and attached properly, and the teats must be disinfected with an approved teat dip following milking. This is to prevent possible spread of mastitis from cow to cow. Similarly, the milk must be handled properly after it leaves the cow. It must be cooled to under 45 degrees Fahrenheit within 2 hours of milking. Plate coolers are often more efficient at cooling milk than bulk tanks and are used on most farms. Bulk tanks manufactured after January 1, 2000 must be equipped with a recording thermometer so that the temperature history of the milk can be monitored. A sample of milk from each bulk tank accompanies the milk truck to the receiving plant. The milk undergoes a battery of tests to assure that it is safe and of high quality before it is accepted for processing. Dairy producers must meet specific requirements for bacteria counts and somatic cells (white blood cells) in milk; and they are paid a premium for high quality milk. No added water or antibiotic residues are allowed, under penalty of losing one's permit to sell milk.