Clean Milk Production in dairy animals

Milking is a process of removing milk from the udder. It is an art requiring experience and skill. Milking should be conducted gently, quietly, quickly, cleanly and completely. Milking aim should be Clean Milk Production. Cows provided with comforts, yield more milk than a roughly handled and excited cow. The act of milking should be so quick that it should be finished within 5 to 7 minutes, so that the udder can be emptied completely as long as the effect of oxytocin is available for a limited time. Milking should be done twice or thrice a day, at regular intervals. The interval should be as equal as far as possible in case of twice a day milking. Abrupt changes in the time of milking affects the total yield.
Milking should be done in a clean area, preferably in a separate milking byre. Pre-milking routine such as washing of cows, feeding concentrate, bringing in milk pails, etc. should be done at regular intervals. Wash the udder and teats with mild antiseptic lotion and dry before milking. Wipe the teats and udder with a detergent dipped cloth after milking. Milker should wash his hands with antiseptic lotion before each milking. Sick cows should be milked at the end to prevent the spread of infection to other normal healthy cows.

Milk ‘Let-down’ or Ejection Mechanism


When milk secretion has continued for a considerable period after the last milking. the alveoli, ducts, glands and teat cisterns are gradually filled with milk. Milk in the cisterns and larger ducts can be removed easily but milk in all smaller ducts and alveoli does not flow out easily due cow and other mammals need a stimulation of nerve endings in the teats that are sensitive to touch, pressure, or warmth is the usual mechanism. The sucking action by calf or massaging the udder or washing with warm water by milker also act as stimuli and are very effective. Stimulation is carried by nerves to the brain which is connected with the pituitary gland which in turn causes the liberation of a hormone oxytocin from its posterior lobe. Oxytocin is carried by blood stream to the udder, where it causes the smooth muscle like cells surrounding each alveolus to contract. The pressure thus created forces the milk out of the alveoli and smaller ducts as fast as it can be removed from the teat.
The let-down mechanism can be stimulated within half to one minutes time. The effective time of the hormone is limited and milking should be completed within 7 minutes to obtain the maximum amount. Complete milking has to be done otherwise the residual milk may act as a breeding place for microorganisms responsible for mastitis.


Milking Procedure


Hand milking and machine milking are the methods practiced in India. The hand milking is the most common method among individual farmers while machine milking is practiced in organised government and military dairy farms.
The milkers milk the cow from the left side. The order of milking the various teats also differs. After let-down of milk the teats are milked crosswise or fore quarters together. Then hind quarters together or teats appearing most distended are milked first. The milk must be squeezed and not dragged out of teats. The first few streams of fore milk from each teat should be let on to a strip cup. It helps to remove any dust from the teat canal and gives milker an opportunity to detect mastitis.


Methods of Hand Milking


1 -Stripping Method


Stripping is done by firmly holding the teat at its base between the thumb and forefinger and drawing them down the entire length of the teat pressing it simultaneously to cause the milk to flow down in a stream. The process is repeated in quick succession. Both hands may be used, each holding a different teat, stripping alternately


2- Full-hand Method


Milking is done by grasping the teat with all the five fingers and pressing it against the palm. The teat is compressed and relaxed alternately in quick succession.


3- Knuckling Method


Many milkers during milking tend to bend their thumb against teat. This is known as knuckling. This method should always be avoided in order to prevent injuries of the teat tissues.
Full-hand milking removes milk quicker than stripping because of no loss of time in changing the hand position. Cows and buffaloes with smaller teats are milked by striping. Full-hand method is better than striping as it stimulates the natural suckling process by calf. Some milkers are accustomed to wet hand milking. They moisten their fingers with milk. water or even saliva. It should be avoided and hands should be perfectly dry while milking.


Machine Milking


Modern milking machines are capable of milking cows quickly and efficiently without injuring the udder tissues. All milking machines are operated by vaccum. Milk is removed from the udder by application of a vaccum to the end of the teat. A positive pressure exists within the udder when it is filled with milk before milking. The pressure within the udder may vary between 40 and 100 millimeters of Hg(mercury) after milk ejection. When the milking machine is applied, the pressure below the teat is applied, is reduced to the vaccum level of the milking machine. This creates pressure difference across the teat orifice. causing it to open and causing milk to flow. The rate of milk removal is partially dependent on the pressure difference across the teat. Machines operating at higher vaccum levels increase the rate of milk flow from the teat.


Clean Milk Production


The following basic hygienic precautions help to obtain maximum amount of Clean Milk Production:


1-Environment

  1. Maintain a clean milk byre.
  2. Avoid wind blown dust at the time of milking by sprinkling water.
  3. Provision of clean water supply.
  4. Control flies by using proper disinfectant.
  5. Locate manure pit at a sufficient distance from the milk shed.
  6. Avoid feeding the cow/buffalo with dusty feed immediately before milking it. Straining helps to remove larger objects which can get into the milk. For straining use either a metallic strainer or muslin cloth.


2- Cow and Utensils

  1. Keep healthy cows free from diseases communicable to man.
  2. Clip long hairs around the flanks. udder, tail and removing caked-up dung and urine stains from time to time.
  3. Daily brush and wash the flanks and tail thoroughly with water containing a little disinfectant, and
  4. Use clean, covered top milking pails.


3- Milker

  1. Milker should be free of contagious diseases.
  2. They should scrub their hands and arms before milking and keep finger nails trimmed.
  3. Wash and dry their hands after milking each animal.
  4. Milk the animals at the same hours as part of daily routine.
  5. Avoid exciting cows before and while milking, and
  6. Wear clean clothes.