The University of Minnesota Extension Dairy Team

Dairy farmers are no realising that lower somatic cell counts (SCC) in their bulk tanks is the future, but there is always room for improvement, even on the best operations.

The University of Minnesota Extension Dairy Team offers these ways that dairy producers can further improve their milk quality.

They are:

1. Keep cows clean and dry at all times. This assures clean teat surfaces and prevents bacteria from entering the teat end.

2. Seek assistance from a qualified dairy professional (veterinarian mastitis consultant , milking machine technician ).

3. Do individual cow SCC tests monthly to help identify herd trends and pinpoint the infected cows.

4. Run a monthly bulk tank culture through a reliable laboratory to find out what kinds of bacteria are causing mammary infections.

5. If bulk tank culture results show a high level of contagious mastitis pathogens (Staphylococcus aureus, Streptococcus agalactiae, or Mycoplasma), identify infected cows by individual cow culturing. Reduce cow-to-cow spread and remove the high SCC quarters from the milk supply.

6. If bulk tank culture results show high levels of environmental pathogens (non-ag streps, coliforms, or staph species), improve bedding management and pre-milking cow prep. Replace all organic bedding in every stall weekly with clean bedding. Every day, replace the bedding in the back half of the stall with fresh, clean bedding. If you use sand bedding, add fresh, clean sand at least once per week. Keep stalls levelled and remove soiled sand daily.

7. Improve consistency in milking procedures. Include a pre- and post-milking teat dip, 10 to 20 seconds of cleaning, at least 30 seconds of contact time for the teat dip, and a thorough teat end wiping before attaching the milking unit. Plan routine to achieve 60-120 second prep-lag time.

8. Include fore stripping during cow prep to identify high SCC quarters and keep milk from those quarters out of the bulk tank.

9. Cull chronically high SCC cows that do not respond to therapy.

10. Treat all quarters of all cows at dry off with an approved dry cow intramammary tube.

11. Consider using a dry cow teat sealer.

12. Provide dry cows with adequate space, ventilation and clean bedding (records indicate that an average of 35% of cows and heifers calve with high SCCs).

13. Keep cows as cool and comfortable as possible during hot weather.

14. Control flies.

15. Maintain milking equipment in good working order. Develop a routine performance check and maintenance program. Replace rubber parts at recommended intervals. Be sure system cleaning is done consistently and properly. h

The Cows Teat!

The Cows Teat!

The cow’s teat has evolved to allow for efficient suckling by the calf but also to provide some defence against damage and infection from mastitis-causing pathogens.

The teat has a large mass of connecting blood vessels at its base called the erectile venous plexus, which, when the milk let-down stimulus occurs, make the teat become more rigid, allowing the milk to be removed by the calf through sucking, or by the milking equipment, without the teat collapsing on itself.

The teat has nerves in the tissues, this allows the brain to react and initiate milk let-down.

Sore and damaged teats can be predominantly painful. Teats vary in shape and size; the more cylindrically-shaped teats are alleged to be less-susceptible to mastitis.

The epidermis is a thick hairless outer skin, containing a thicker layer of keratin (a substance found in hair and hooves) than is found in normal skin. This gives it a much more rugged structure to cope with the demands of being suckled. It has however no sweat or sebaceous glands to lubricate it like normal skin, and so is more prone to drying and cracking. The epidermis also has a large number of nerve endings.

The dermis is the second layer of the teat wall and carries the nerves and blood vessels.

There is a layer of muscle, giving the teat strength and structure, and a circular sphincter muscle around the teat canal.

The teat cistern is lined with epithelial cells, which are square-shaped and are able to move apart, allowing white blood cells to enter the structure as an immune system response to bacterial infection.

The teat canal is approximately 9mm in length and has a lining comprised of folded epidermal tissue (similar to skin, but containing more keratin), covered by a thin lipidised film. This film is hydroscopic (it repels liquids).

There is also a structure known as the rosette of Furstenberg, which has an important role in detecting bacterial infection and initiating an immune response. :

A brief History of the Cow – Bovinae species

The original range of wild cows was northern Africa, Europe and southern Asia. Cows were domesticated between 10,000 and 6,500 years ago by cultures great distances from each other. Typical western cattle are from the older strain, which was most likely first domesticated in Turkey.

The most genetically diverse population of cattle is found in the Taurus Mountains of Turkey, which strongly indicates that cattle were first domesticated there. There is evidence of domesticated cattle remains in China at around the same time, about 10,000 years ago, but it is unclear if these cattle were traded from Turkey or native to China. What is known is that domesticated cattle from Turkey spread to Europe and Africa,

The Pleistocene Epoch is typically defined as the time period that began about 2.6 million years ago and lasted until about 11,700 years ago. The most recent Ice Age occurred then, as glaciers covered huge parts of the planet Earth. Evidence has shown that wild cows roamed this period, classed as a slow moving prey species.

Cattle are prey species. Their eyes are located on the sides of their heads, allowing them to capture movement around them. But they take longer to focus on specific objects. Their excellent peripheral vision creates a panorama effect on their sides. Their hearing tends to be sensitive to high-pitched noises, dairy breeds more so than beef breeds.

The cow has always been part of the bio sphere and Archaeologists and biologists are agreed that there is strong evidence for two distinct domestication events from aurochs in the near east about 10,500 years ago,

Most mammals, including humans, can tolerate milk as infants, but after weaning, they lose that ability. Only about 35% of people in the world are able to digest milk sugars as adults without discomfort, a trait called lactase persistence so the herd cow was used for meat and clothing.

The 18th century saw the birth of the first breed Systematic, selective breeding and genetic isolation finally led to the development of hundreds of different breeds, which over time became also integral parts of local tradition highland, welsh black, Aberdeen Angus.

Herbivores, cattle feed primarily on grasses and stems. To pull up grass or a plant, a bovine twists its tongue around the plant and cuts it off with its bottom teeth. In place of upper incisors, a bovine has “dental pads” ideal for grinding coarse grasses and other plant materials. The bovine is a ruminant, possessing a four-chambered stomach. The four chambers are the rumen, reticulum, omasum and abomasum. Food first goes through the rumen and reticulums, where bacteria help break it down into cud, substance cattle regurgitate and chew again. Then the food goes through the omasum and into the abomasum. This digestive process can take 70 to 100 hours

Humans have survived ice ages and deadly pandemics to become the dominant species on Earth, even if our reign over the planet barely represents a blip in a geological record that has seen countless living organisms come and go. We have adapted to live almost anywhere, Cows, for instance, are easily domesticated.

For many centuries, smallpox devastated mankind
An estimated 300 million people died from smallpox in the 20th century alone ,
inserted pus extracted from a cowpox pustule on the hand of a milkmaid, into an incision on the arm of an eight-year-old boy, James Phipps and the vaccine was born.

Would the Human race had survived without the Cow ?

recent research on over milking

The practice of milking and stripping all cows completely during each milking could be leading to teat damage in your herd.

Over milking can damage teat ends and compromise udder health ‘putting cows at greater risk for infection. But a simple test can help you determine if you are over- or under milking.

The recommendation to milk all cows completely ‚every time ‘has been reviewed due to recent research and field experience. It is impossible to milk a cow completely dry. There will always be some milk in the udder, even after “complete” milk out, because she is constantly making milk.

In the past, it was believed that all milk needed to be removed from the udder to maximize milk yield. However, breeding for high milk yields has provided cows with a high alveolar capacity. Due to this, cows are more efficient as milk producers.

Over milking starts when the milk flow to the teat cistern is less than the flow out of the teat canal. Fluctuations within the mouthpiece chamber vacuum can occur. If the vacuum in the cistern is higher than beneath the teat, reverse pressure across the teat canal may increase bacterial infection.

Reverse pressure gradients occur only during milking of empty teats, and over milking will therefore increase the possibility of bacteria entering the teat.

Teat-end health is also greatly affected by over milking. Hyperkeratosis of the teat, which is a thickening of the skin that lines the teat canal and external orifice, is often experienced in herds with long unit-on times.

Hyperkeratosis doesn’t allow for teats to be thoroughly cleaned and can lead to bacteria being left behind‚which also can lead to an increased somatic cell count.

many factors could be at fault. Milking machines must be properly maintained, and if automatic detachers are being used, adjust for timely removal of the milking unit. If your farm manually detaches units, employees must be more consistent in removing the unit as soon as “end of milking” is reached for each animal.

Timely unit attachment and proper let down, quiet cow handling and timely unit adjustment, and proper alignment are also critical.

A few simple steps can prevent over milking and can help decrease your overall herd somatic cell count. By following these guidelines, your herd can reach optimum udder health.

Cow Flow into Parlour .

Poor cow flow can affect costs and increase standing time – and therefore reduce feeding, drinking and lying times. These issues have poor consequences for foot health, and for milk production.

Cows milked in poorly maintained milking equipment will be reluctant to come into the parlour.

Check vacuum levels, automatic cup remover (ACR) settings and milking liners and also think about the standing point of the cow in the parlour.

Milking bigger cows in a parlour that was designed 16 years ago for smaller animals can make standing uncomfortable.

This can lead to less-effective milk let-down and incomplete milk-out.

Providing a small rise in the floor towards the parlour can also encourage cows to face and move forwards.

Installing rubber mats in a strip at the entrance to the parlour can draw cows towards the parlour.

Fitting rubber matting in the milking stalls, on exit and at any sharp turns can aid comfort and thus flow.

Cow flow typically becomes a problem on farms that have expanded and either extended or put in bigger parlours.

This is a particular problem when the size of the collecting yard has not changed and cow numbers have increased.

This means cows can be too tight in the collecting yard stopping the dominant or milking entry cows unable to move easily through the herd and into the parlour.

If used too much, a backing gate can push cows too close together and reduce space per cow, reducing cow movement.

The key is to set the gate’s sensitivity and resistance, so that when it comes into contact with a cow it stops.

Linking the rear gate of the parlour to the backing gate also helps to stop the space per cow from being compromised.

Never bunch cows with a gate this has a negative affect an can cause stress .

Cows do not like moving from light to dark so it’s important to minimise shadows.

They see shadows as holes.

Cows should move in a straight line in and out of the parlour as sharp bends can affect movement.

Avoid strangers from entering the parlour during milking .

Is you Milking Machine Flooding ?

The milking machine is the most important piece of equipment on the dairy farm. It is used more often and more hours per year than any other piece of equipment, including the farm tractor.

When milk completely fills any tube or line between the teat end and the vacuum pump, the system is said to be flooded. Placing a solid column of milk in the air column slows its movement. If air is being admitted to the system behind the column of milk, the vacuum level will lower. Some researchers feel that flooding alone is detrimental and vacuum fluctuation is secondary in causing new udder infections. Their opinion is based on the possibility of milk from an infected quarter mixing in the flooded claw and then contaminating the teat end of an uninfected quarter. This is a possibility. One study showed that impact forces on a teat end do occur when the liner opens.

The Following is a list of factors involved in flooding.

Fast milking cows.

Liner tail piece of inadequate capacity.

Small Claws and wide ratios.

Elevating milk with milking vacuum.

Milk line too small for number of milkers.

Inadequate milk line slope.

Risers.

In line milk filters.

Elbows in milk line.

Improperly placed milk inlets.

A 300 ml capacity claw piece enables a cluster to handle the fastest milking cows with no danger of flooding whether on 4 x 1 or 2 x 2 pulsation, the 19mm milk nipple allows maximum flow of milk and vacuum through the milk tube.

Most short milk tubes are now 8mm plus

Most direct to lines are 75mm, there is a maximum number of units on a straight and looped line.

Milk lines should have a continuous and even fall towards the receiver jar, with a minimum of 10 mm (1 cm) of drop for every metre of pipe.  This translates into a minimum decline of 0.5%.

The more milkers in the parlour the more chance of slugging increase the fall.

The Above Graph shows a brand new parlour with slugging in the milk line due to a sharp bend , this value only just complies .

The flow of milk inside the milk line should be at a level of less than 50%, i.e. there should be more air above the level of milk than milk below.  This is called “stratified flow

The milking cluster requires air vents so that the milk lines do not become flooded.  The air vents are located either in or near the claw or in the liner. 

Checking your pulsation ratio to ensure quick gentle milking

Lifting milk can increase the length of the milk vacuum slug and reduce the vacuum level.

There should be no risers on the milk line

Having sharp bends will affect the movement of airflow milk flow and can cause flooding.

The Milking Machine does not give the cows mastitis it can spread pathogens or damage the teat skin .

I am still testing poorly installed milking equipment, why no fit it correctly? “

Think about Cubicles ?

There are a number of cubicle features that can affect welfare. Ideally, a cubicle will allow an animal to lie down and rest without hitting or rubbing against partitions.

An appropriate cubicle length will prevent soiling of the bedding and reduce risk of injury. Cubicles that are too short for the cow or partitions with rear support legs may cause rubbing and swelling on the hocks. A good depth and cleanliness of cubicle bedding will create comfort and also prevent knee swelling and hock injuries.

The cubicle must be wide enough for the cow to lie comfortably but narrow enough to prevent her from turning around. The cubicle also needs to provide the natural rising behaviour of the cow. Brisket boards that provide space for the cow to lunge forward when she kneels down to reach a lying position will facilitate the easy movement to lying which may prevent awkward twisting of the neck, back and front legs. The cow should not come into contact with the cubicle partition in such a way that could cause injury.

When a cow rises from a lying position, she lunges forward to transfer the weight from her hindquarters onto her front legs. She will then raise her hindquarters before raising her forequarters. To accommodate this transfer of weight, the cow thrusts her head forward as she lunges. Studies have shown that a cow requires between 0.7 and 1.0m of space in front of her to rise easily. If the forward lunging space is constrained, she will have difficulty in rising. She also throws one foot forward when rising and any barrier to this normal activity may compromise the way she raises and possibly lead to lameness and reduced cubicle occupancy.

When there is not a cubicle for every cow, lying time reduces, aggressive interactions between cows increase, incidences of lameness and mastitis both increase. Should be at least as many cubicles as there are cows in the house. However, it is essential that all cubicles are functioning by the cows. If some cubicles are less attractive or broken then it is necessary to have more than one cubicle per cow.

A paper published in the USA reported that for every 10% increase in stocking rate above 80% occupancy, there is reduction of 0.73kg milk per cow per day.

Animals which are lower in the social hierarchy spend between 10 and 45% of their day standing in the passages. As a result, subordinate cows suffer more sole, interdigital and heel lesions. Providing additional cow places in the cubicle system will allow these cows to lie without risk of aggressive interactions. Other studies have demonstrated that not all cubicles are occupied to the same degree, with some being more preferred to others. This will also result in subordinate cows standing for longer periods of time.

There is also considerable debate regarding the location of cubicles within a building and how this can affect occupancy. In a Canadian study, cubicles closest to a feed passage were occupied for 68% of the day compared with only 48% occupancy for cubicles which were further from the feed area. In addition, cubicles at the end of rows were occupied 25% less than cubicles located in the centre of the row.

This may be because the cows have to walk further to food or have to navigate certain physical barriers (narrow passages) or social obstacles dominant cows) on their way to more distant cubicles. Work carried out in Cambridge in 1990 indicated that the movement and resting of subordinate animals is heavily influenced by the location of dominant animals