HANDLING OF MILKING MACHINES & ITS ROLE IN MODERN DAIRY FARMING
by-DR RAJESH KUMAR SINGH, JAMSHEDPUR, JHARKHAND,INDIA
9431309542,rajeshsinghvet@gmail.com
The most tough job in the dairy farming is to milk the cow properly, timely with hygienic condition.Today in India, the dairy entrepreneurs are starting their dairy startup mostly in the periphery of city due to the huge gap of demand and supply chain but they generally faces the problems related to labour management particularly for milking the cows and sanitation in the dairy farm. In order to short out these problems the automation is necessary components. Milking management is one of the most important and crucial activities in the milk production chain. The milking machine is unique in the sense that it is one of the few machines which comes in contact with farm animals on a regular basis. It is therefore very important that these machines are correctly installed, maintained in excellent operating conditions, and used properly.
Early attempts at milking cows involved a variety of methods. Around 380 B.C., Egyptians, along with traditional milking-by-hand, inserted wheat straws into cows’ teats. Suction was first used as a basis for the mechanized harvesting of milk in 1851, although the attempts were not altogether successful, drawing too much blood and body fluid and causing congestion within the teat. To encourage further innovations, the Royal Agricultural Society of England offered money for a safe, working milking machine. Around the 1890s, Alexander Shiels of Glasgow, Scotland, developed a pulsator that alternated suction levels to successfully massage the teat and extract milk. That device, along with the development of a double-chambered teat cup in 1892, led to milking machines replacing hand milking. After the 1920s, machine milking became firmly established in the dairy industry. Today, the majority of all milking in organized farms is carried out by machine.
How automatic milking works——–
Modern milking machines are capable of milking cows quickly and efficiently, without injuring the udder. The working principle of the milking machine is to imitate the suckling of the calf. The milking machine performs two basic functions:
• It opens the streak canal through the use of a partial vacuum, allowing milk to flow out of the teat cistern through a line to a receiving container.
• It massages the teat, which prevents congestion of blood and lymph in the teat.
The milking unit is the portion of a milking machine for removing milk from an udder. It is made up of a claw, four teatcups, (shells and rubber liners) long milk tube, long pulsation tube, and a pulsator. The claw is an assembly that connects the short pulse tubes and short milk tubes from the teatcups to the long pulse tube and long milk tube (cluster assembly). Claws are commonly made of stainless steel or plastic or both. Teatcups are composed of a rigid outer shell (stainless steel or plastic) that holds a soft inner liner or inflation. Transparent sections in the shell may allow viewing of liner collapse and milk flow. The annular space between the shell and liner is called the pulse chamber.
Milking machines work in a way that is different from hand milking or calf suckling. Continuous vacuum is applied inside the soft liner to massage milk from the teat by creating a pressure difference across the teat canal (or opening at the end of the teat). Vacuum also helps keep the machine attached to the cow. The vacuum applied to the teat causes congestion of teat tissues (accumulation of blood and other fluids). Atmospheric air is admitted into the pulsation chamber about once per second (the pulsation rate) to allow the liner to collapse around the end of teat and relieve congestion in the teat tissue. The ratio of the time that the liner is open (milking phase) and closed (rest phase) is called the pulsation ratio.
The four streams of milk from the teatcups are usually combined in the claw and transported to the milkline, or the collection bucket (usually sized to the output of one cow) in a single milk hose. Milk is then transported (manually in buckets) or with a combination of airflow and mechanical pump to a central storage vat or bulk tank. Milk is refrigerated on the farm in most countries either by passing through a heat-exchanger or in the bulk tank, or both.
In the photo above is a bucket milking system with the stainless steel bucket visible on the far side of the cow. The two rigid stainless steel teatcup shells applied to the front two quarters of the udder are visible. The top of the flexible liner is visible at the top of the shells as are the short milk tubes and short pulsation tubes extending from the bottom of the shells to the claw. The bottom of the claw is transparent to allow observation of milk flow. When milking is completed the vacuum to the milking unit is shut off and the teatcups are removed.
Milking machines keep the milk enclosed and safe from external contamination. The interior ‘milk contact’ surfaces of the machine are kept clean by a manual or automated washing procedures implemented after milking is completed. Milk contact surfaces must comply with regulations requiring food-grade materials (typically stainless steel and special plastics and rubber compounds) and are easily cleaned.
Most milking machines are powered by electricity but, in case of electrical failure, there can be an alternative means of motive power, often an internal combustion engine, for the vacuum and milk pumps. Milk cows cannot tolerate delays in scheduled milking without serious milk production reductions.
Advantages of milking machines——-
Some of the advantages of milking machines are:-
• Saving of labour expenses.
• Reduction of dependency on skilled farm workers.
• Enables rearing of larger herd strength.
• 3-4 times faster than hand milking.
• Increase in the milk yield.
• Increase in the quality of milk.
• Reduces stress throughout the lactation by creating good milking routines.
Limitations:——————–
• Some of the older cows which are accustomed to hand milking may not adjust to machine milking.
• Standby power supply is essential.
• High initial investment and training of staff.
• Negligence in following the strict cleaning procedures would lead to severe contamination and higher incidence of mastitis.
• Greater water requirement for cleaning of equipment.
• Prompt service and availability of spares is essential.
With a correctly specified, installed, operated and maintained milking plant you will be rewarded with a volume of milk according to your cows’ present ability and with a quality that meets the highest standards.
The payment for your milk is always related to the volume produced and in most cases also influenced by the quality of the milk measured in some way.
• Milk quality can be measured as fat and protein content and then valued as food for human consumption with a certain content of nutrients.
• Milk quality can be measured as total bacteria content (TBC), which measures the hygienic standard of the milk.
• Milk quality can also be measured as somatic cell content (SCC), which measures the animal health or level of mastitis infections in the udder.
Milk quality can also be measured as odor (smell) and taste, which is a measurement of palatability.
• Finally contaminations of antibiotic residues, other impurities and water are seen as serious deteriorations of the milk quality.
TBC and SCC are the accepted measurements used to set standards in most OECD countries and international trade regulations. They are also used for various bonus and penalty payment schemes to producers throughout the world.
Types of milking machines/systems—————-
• Portable milking machines : These are ideal for small herds (upto 20 cows)
• Barn milking systems : These are installed on farms where cows are kept tied in stalls and no separate milking parlour is present (20-100 cows)
• Milking parlours : These are constructed on large farms; they are of various types (more than 100 cows)
Selection of appropriate milking machine system————
System design—-
For milking on the individual farm you need to specify a plant that best meets the requirements on the particular farm.
• You need to consider how many cows, whether they are tied up or loose and to what extent they are pasture fed.
• You need to know actual and intended yield levels as well as calving patterns.
• Labor cost, qualifications and availability will decide level of automation.
• Technical matters like existing buildings, access to electric power, water quality and availability and access roads will influence plant specifications.
• Financing and operation costs have to be considered.
• Local laws and regulations have to be considered.
Points to be considered————-
• Technically you have to design the vacuum system to handle milk extraction, milk transport and cleaning.
• It has to operate with a stable level to assure optimal extraction.
• It has to consider disturbances like kicked off units or air inlet during putting on the unit.
• It has to have a capacity to transport the milk without too strong agitation which will harm the milk quality.
• Finally it has to have a capacity giving strong turbulence in the cleaning water during the cleaning process.
• The pulsation system has to give gentle milking with sufficient capacity to handle high flows of milk without harming teats during low flows. You want the milking to be fast but not harmful.
• The capacity for milking has to be matched by the cooling capacity to safeguard the milk quality.
• Automation is mostly seen as a way to save on labor cost, but automation can also be a quality assurance by safeguarding a certain work process.
Table below can give an idea of different parlour designs operational parameters in comparison with each other. The figures presented in this table can be used as a rough guide for initial assessment.
Parameter/Parlour design Throughput Labour costs Personnel skills Running costs Relative costs
Herringbone parlour 50% 90% 50% 50% 50%
Swing-over parlour 30% 100% 50% 70% 40%
Rapid exit parallel parlour 80% 80% 90% 70% 80%
Rotary parlour 100% 60% 100% 100% 100%
Barn milking systems/milking pipelines are suitable for farms where the cows are kept tied in stalls.
Portable milking machines are useful for farmers with small herds, and when the animals cannot be brought to the parlour for any reason.
Introducing machine milking———–
The concept of machine milking should be introduced slowly and by persons whom the cows are used to and feel comfortable with under the supervision of an expert from milking machine manufacturer.By carefully following the mentioned steps, a successful introduction should be possible.
• Training of personnel. Training of milkers should be done by a person from the milking machine company. This person has good knowledge about biology of milking, machine milking as well as with the design, function and maintenance of the milking equipment. The training should include introduction procedures, milking routine, handling of the machine, cleaning and maintenance as well as certain aspects of the day-to-day service of the machine.
• Installation of the milking machine in the barn and any other modification in the barn should be made well in advance of the changing to machine milking.
• It is most appropriate to start with heifers since it is easier to habituate heifers than older cows to machine milking. Older cows may have been hand milked by a certain routine for several lactations and may respond negatively to a change in routine. Heifers on the other hand are not accustomed to any specific routine and are more likely to accept machine milking as well as hand milking. Furthermore their udders and teats are more uniform and not damaged by previous milking. Liner slip and other negative effects of machine milking is therefore less pronounced in heifers. Note that heifers should not be hand milked but directly introduced to the machine. They may get accustomed to the noise of the vacuum pump etc. by participating in the milking routines prior to parturition.
• Calm animals that are comfortable with hand milking should be selected. The udders and teats of the animals should be uniform with respect to conformation and size. Cows in heat or unhealthy animals or animals with previous let-down-problems should not be selected.
• Milk the old and selected animals as usual by hand but let the vacuum pump run during milking. This will make the animals accustomed to the noise. Put the pump on before actual milking, but after the cows have been tied up, otherwise the animals may be startled by the sudden noise. Repeat the procedure (usually 2 to 4 times) until all buffaloes are accustomed to the noise. It is better to repeat this procedure once or twice more until all cows are comfortable, than rushing into the next step.
• Bring the milking machines into the barn. Connect them to the airline and place them at each buffalo’s place at the same time as hand milking is carried out. This will allow the buffaloes to get used to the ”ticking” sound of the pulsator. It will give them a chance to look at the machines and smell them and may be even taste them. Make sure though, that they do not chew on them! Move the machines to the next cow in order of milking. This makes the cows used to machines being moved around. The procedure should be repeated (usually 2 to 4 times) until all the animals have accepted the presence of the machines.
At this stage, presumably all cows will be well accustomed to the new routine. If some cows are still showing signs of nervousness or stress, it is recommended to repeat the above mentioned steps until the animals are calm. Cows that have not accepted being milked by machines after this procedure should be returned to hand milking. One or two frightened or uncomfortable cows might cause major disturbances in the whole herd.
Consistency with respect to milking routine including pre-milking preparation should be applied from the beginning of the introduction period. The regular milker should carry out the machine milking during the introduction period.
When the cluster is firmly attached to the udder, the milker should stay with the cow to see that she is comfortable. Soft talking and brushing and scratching are the best ways to calm an animal. These first sessions of machine milkings usually require longer time than the following. However, this time is well worth spending in order to ensure calm and easy-milking cows in the future.
Operation of milking machines————
Milking cows is a highly qualified job that will benefit from a persistent use of correct routines.
• Before starting milking make sure all equipment and tools are at hand and in proper condition. Use clean suitable clothing and wash your hands thoroughly before starting milking.
• Always handle animals with care and in a calm and considerate way. No yelling or beating if you want them to give you all their milk.
• Clean and massage the cow’s udder. Use dry cleaning if the udder is clean. If it is so dirty that wet cleaning is required make sure you wipe the teat dry after cleaning. Use disposable cloths for each cow or individual cloths that are cleaned in a washing machine between every milking.
• Premilk by hand in a test cup. Take a few squirts from each teat and check for flocculation or blood.
• In some countries a special pre dip is used to disinfect the outside of the teat. This will eliminate infections to spread from the outside of the teat to the inside of the same or other teats milked with the same unit.
• Put on the milking unit within one minute after preparation.
• A persistent routine is very important for this action as the cows will develop a let down reflex that is adjusted to such a routine.
• Monitor the milking and adjust the unit if it starts squeaking or if the cow appears uncomfortable.
• Take off the unit when the milk flow has ceased or is very low. Check that the udder is empty before you remove the unit. Avoid developing habits were all the cows expect you to aftermilk with machine before taking off. If you use automatic take off units do some random checks that the cows are properly milked.
• Teat dip the cows within one minute after take off. This will safeguard disinfection and protection of the teat canal while it still is open.
Register the observations you do on the individual cows during milking. In many production systems milking is the only time of the day when you are close to all the individual lactating cows.
• Treated and sick cows shall always be milked separately and after all the healthy cows.
• Cows develop habits. If you establish and maintain a persistent milking routine for every milking the cows will feel comfortable and respond positively with an even production.
Cleaning———-
The milk from a healthy animal is almost sterile when it leaves the udder. To maintain a high quality of the milk it has to be handled in a clean installation. It is therefore necessary to clean the milking plant thoroughly after each milking.
• Sufficient and good quality water is required to achieve a satisfactory cleaning result.
• Water heating capacity has to match the requirements from the cleaning procedure.
• Detergents have to be selected to work with the actual water quality and dosed in accordance with the instructions given by the equipment supplier.
• The hand washing procedures shall follow the supplier’s instructions.
• If there is an automatic cleaning unit installed it has to be adjusted to the requirements of the plant and water quality and operated according to instructions.
• Make sure the cooling tank or cans are equally well cleaned and that you don’t forget any part or connection in the whole milk handling chain.
• Avoid standing water in and on the cleaned equipment after cleaning and before next milking. Allow drying by having good ventilation or air movements.
Cooling—————-
To avoid rapid deterioration of the milk after milking it shall be cooled down to 2-4C within 2 hours. If you don’t have access to electric power and/or artificial cooling it is important that you cool the milk by keeping it in the shade and putting it in water from the well or other cool water source. If you can’t cool the milk, frequent milk collection at least once per day is required.
• If you have a cooling tank it has to have the capacity to cool down the milk within 2 hours. You also have to make sure the milk is not collected before the milk is cooled down.
• The agitation of the milk in the tank has to be gentle to avoid milk quality deterioration.
• If you can avoid mixing warm milk in cooled that is an advantage from quality point of view.
• Clean the tank immediately after the milk has been collected by the truck.
Maintenance——————-
• For a continuous trouble free operation with high quality milk regular maintenance and exchange of wear and tear parts is necessary.
• A serious supplier and installer will offer a scheduled plant service to give the required maintenance.
• Such a service will include dismantling and a complete cleaning of the plant, exchange of all required wear and tear parts according to established time limits, checking of all essential functions and parameters and a complete test run.
• Such preventive scheduled services will markedly reduce operational breakdowns that by experience always will be more costly in the longer perspective.
• A preventive service works as an assurance and reduces production losses and gives peace of mind.
Milking machines for buffaloes————–
Buffaloes have been used for milk production for centuries. They have not been subjected to the same upgrading and breeding like cattle of the western world. However, the buffalo is an excellent milk producer, given the correct circumstances. Milking the buffalo is not a difficult task. One should, however, take care not to implement cattle milking techniques directly on the buffalo cow.
Anatomy of the buffalo udder and teat—–
The buffalo has an udder similar to the cattle in the gross anatomy. Generally, their teats are larger than those of cattle. According to several studies, cylindrical forms of the teats are most common in the Murrah breed. The front teats are, on average, 5.8 cm to 6.4 cm long and their diameter is approximately 2.5 cm to 2.6 cm. Respective figures for the hind teats are 6.9 cm to 7.8 cm and 2.6 to 2.8 cm.
The hind quarters of the udder are slightly larger than the front ones and contain more milk. The approximate ratio is 60:40 (hind:front), as for cattle. It takes a longer time to milk the hind quarters.
The anatomy of buffalo teats is slightly different from cattle teats. The epithelium of the streak canal is thicker and more compact in buffaloes than in cattle. The sphincter muscle around the streak canal is thicker in buffaloes than in cattle. More force is therefore required to open the streak canal. The teat sphincter tonus has been reported to be at least 400 mmHg negative pressure in buffaloes. This is the cause of buffaloes being ”hard milkers”.
In cattle, the milk is synthesized in the alveoli and is periodically transferred to the large ducts and cisterns of the mammary gland and the teat. This is not the case in the buffalo, instead, the milk is held in the upper, glandular part of the udder, in the alveoli and small ducts. Between two milkings there is no milk stored in the cistern. Hence, buffaloes have no cisternal milk fraction. The milk is expelled to the cistern only during actual milk ejection. The same phenomenon is seen in Chinese Yellow cows and Yaks.
Because of the absence of cisternal milk between milking, in the teat cisterns, the teats are collapsed and soft before let down. This is contradictory to the bovine cow, where the teats can be very hard and firm due to the presence of milk in the teat cistern.
Physiology of milking—————
Buffaloes are said to be slow and hard milkers because of their slow milk ejection reflex and their hard teat muscle sphincter. The milk ejection reflex appears to be inherited to some extent but it is also a product of the environment. In buffaloes, the let down time averages 2 minutes but may be as long as 10 minutes. The reasons for this are not fully understood.
One reason for the longer let down time of milk for buffaloes is probably the different anatomy of the udder as compared to the dairy cow. In the buffalo, the udder cistern is absent or has a very small volume and therefore there is little or no cisternal milk available. This furthermore leads to no intramammary pressure in the cistern which would otherwise help the milk flow. In cattle, the milk is already stored in the large cistern, and milk is available for extraction immediately after preparation. The high intramammary pressure contributes in pressing out the milk.
The intramammary pressure increases at the onset of milking. It is highest during the peak flow and decreases there after to zero at the end of milking. The pressure is higher in buffaloes during milking than in cattle. The intramammary pressure varies between individuals and milkings. Its’ level is not always indicative of a high milk production.
Let down time seems to be negatively correlated to milk yield. Let down time is shorter in early and middle stage of lactation as compared to in late lactation. A faster flow of milk is observed when the yield is higher.
If buffaloes are carefully selected for yield and ease to milk, improvement in these characteristics is possible.
Machines for milking buffaloes—————-
Since the udder and teats in buffaloes are different compared to cattle, milking machines for cattle have to be modified in order to fit buffaloes. In general, a heavier cluster, a higher operation vacuum and a faster pulsation rate is required. Results from recent studies in India indicate that it might be possible to reduce the cluster weight and the frequency of liner slip by applying an appropriate combination of liner design and cluster weight.
It is not only the total weight of the cluster that is important, but also the distribution of its weight on the udder. Unequal weight distribution can cause uneven milk output. The long milk and vacuum tubes should be aligned and stretched to ensure equal weight distribution of the cluster on the udder.
Milking characteristics depend upon vacuum levels and pulsation rates among others. Studies on Egyptian buffaloes revealed that a vacuum of 51 kPa and a pulsation rate of 55 cycles/min led to much longer milking times than a vacuum of 60 kPa and a pulsation rate of 65 cycles/min (6.21 min. compared to 3.18 min.). The higher vacuum level, however, caused a significant increase in the somatic cell counts. Highest milk yield within an acceptable time were found when using 56 kPa and 65 cycles/min. In all trials a pulsation ratio of 50:50 was used. Studies in Pakistan indicated that the pulsation rate and ration should be 70 cycles/min and 65:35 respectively for Nili-Ravi buffaloes.
In Italy, the majority of farms use the same machines for both buffaloes and cattle. It is a simple ”cattle machine” with one vacuum level operating at approximately 40 cm Hg.
In India, recent trials have been made with milking with Duovac from Alfa Laval Agri. While milking with the Duovac, the impact of milking on empty teats is minimized. The Duovac is a milk-flow controlled milking system which synchronises with each individual animal’s milk ejection and milk flow pattern. Milking commences on low vacuum (vacuum level of 38 kPa, 48 cycles/min pulsation rate and pulsation ratio of 65:35) and when the milk flow from the udder increases above 0.2 kg/min, the vacuum automatically increases to the normal milking vacuum level (vacuum level of 55 kPa, 70 cycles/min pulsation rate and pulsation ratio of 65:35) and stays that way until the milk flow falls below 0.2 kg/min. The DuovacTM was found physiologically correct for the animal since it helps in gently stimulating let-down and is also more gentle to the teats after the peak flow.
Milking machine suppliers———
• DeLaval India
• Milkwell milking systems
• Krishna Industries
• GEA Farm Technologies
• Tarimak
• Manual milking machine
• Indiamart
• Tradeindia
