Teat condition is udderly important

Regular monitoring of teat condition is a useful tool for assessing the milking routine and milking machine operation. But often this can be overlooked with automatic cup removers and automatic teat sprayers.

With mastitis the biggest health issue facing the dairy industry, teat health becomes a key determinant for good milk quality and preventing udder infections. Regular teat condition scoring should therefore be considered just as important as body condition scoring and locomotion scoring to keep mastitis rates and somatic cell counts in check.

What should I look for as indicators I may have a problem?

There are many changes which can be monitored to provide insight into what is happening during the milking process.

Things to look out for have been highlighted below:

COW BEHAVIOUR

Previous experiences are remembered by cows so observing cows as they enter the shed/bale may provide insight into recent milking experiences. Once they are standing on the platform or in-shed observe for signs of shifting feet, stomping, kicking cups off early, or delays in milk let down as this could indicate they are uncomfortable. Being agitated after cups-off may also indicate uncomfortableness and possible teat damage.

TEAT SKIN CONDITION

Teat skin condition is one of the cow’s major defences against mastitis providing an essential barrier against bacterial invasion. Broken skin, cracking, chapping, and rough skin harbours more pathogenic bacteria, allowing colonisation of mastitis causing bacteria such as Staph aureus. Dirty teats are also prone to problems as mud strips away protective oils and moisture from the skin with a consequent loss of skin elasticity.

Evaluate the skin by lightly rubbing the teat surface with a finger and classifying as either normal (smooth, soft, supple), dry (scaly, rough, no cracking) or with open lesions. Dryness can be accelerated in cold or windy conditions and the presence of chapping may indicate poor teat spraying technique or inadequate proportions of emollient. Cows with dry and badly cracked skin are often slow milkers and the increased time with cups on can lead to more teat damage.

TEAT ENDS - OPENNESS OF THE TEAT ORIFICE

Teat end condition should be assessed within 1 minute of cluster removal and before teat spraying. A closed teat end orifice is particularly important as this forms a critical barrier to prevent bacteria from entering the udder. Post-milking openness of the teat orifice (about the size of a match stick, >2mm in size) can be lined to high vacuum pressures, overmilking, heavy cluster weight or liner tension.

TEAT ENDS - HYPERKERATOSIS

Milking machine induced teat damage commonly occurs at the ends of teats and appears as roughness or a callous. The skins natural mechanism against regular damage is to thicken by producing extra layers of protective keratin in a process called hyperkeratosis. Low levels of hyperkeratosis appear as smooth rings and are a normal response to machine milking, but increased hyperkeratosis is associated with increased risk of intramammary infection.

Rough teat ends with cracks and pits provides a place for bacteria to survive and multiple outside the udder with close proximity to the teat orifice. Rough teat ends also alters skin elasticity around the teat opening and can hamper teat closure after milking. Skin thickening can also extend up the teat canal increasing the risk of new infection.

The degree of hyperkeratosis correlates to the degree of mechanical force placed on the teat while the cups are on. Some factors may include high vacuum pressure, prolonged overmilking, incorrectly set threshold for automatic cluster removal.

Assess for teat end damage around the teat opening. No rings or slightly raised smooth rings are acceptable, with the target of <20%. Roughened raised rings indicates a breakdown in skin integrity and is worthy of investigation

SWELLING AT OR NEAR THE BASE OF TEATS – RINGING

A visible line, thickened ring or swelling above the level of the liner mouthpiece may indicate high vacuum pressure, over-milking or teat cup crawl.

TEAT FIRMNESS/HARDNESS

Teats should feel soft and compliant after milking. Swollen, hard or firm teats or flattening at the teat end (wedging) indicates milking induced changes.

TEAT COLOUR AT THE END OF MILKING

Red or blue discolouration on the teat surface after cluster removal may point to problems with blood supply to the teat while the cups are on.

Red bruising or blood spots/blisters typically indicates damage to blood vessels, while blueness may indicate blood flow has been cut-off. Possible causes include high milking vacuum pressure, prolonged over-milking, pulsation failure or incompatible liner/shell.

TEAT LESIONS

Any open lesions can harbour contagious pathogens such as Staph aureus but also cause pain and discomfort for the cow during milking.

Sores or lesions on teats may also be due to infectious causes such as viral and bacterial infections and should be isolated from the milking herd and milked last to reduce of further spread to healthy cows. Some lesions can be contagious to humans so wearing gloves and disinfection is recommended.

Regular checks of teat condition are recommended to pickup and identify emerging issues and to take action.

TEAT SPRAY COVERAGE

Post-milking teat disinfection aims to kill bacteria that may have been transferred onto the teat surface during the milking process before they have the chance to enter the udder via the teat orifice. So, it stands to reason, teat disinfection will only be effective if it covers the entire teat. Teat spraying the entire teat surface is particularly important to contain contagious bacteria such as Staph aureus and Strep agalactiae.

Teat spray coverage can be checked using a paper towel wrapped around each teat to see if all the surface of the teat has been sprayed. Each cow should be receiving at least 20mL per milking for good coverage. Improving spray coverage may require an adjustment to manual techniques or recalibration of the automatic spray unit.

TEAT SPRAY MIXES

An accurate ratio of teat spray, emollient and water is a critical factor for maintaining teat softness. Emollients such as glycerine are effectively moisturisers/conditioners to maintain suppleness of teat skin, taking moisture from the air and trapping it on the skin surface to allow rehydration. Emollient concentrations should be determined once water has been added to the mixture and adding extra to achieve a concentration of 12-16%. It’s important not to take a one-size-fits-all approach or to switch to seasonal mixes, but rather be guided by what the teats are telling you.

CLUSTER ALIGNMENT & LINER SLIP (SQUEAKS)

Incorrectly aligned cups can lead to uneven milking out.

Liner slip, sudden fluctuations in vacuum, or rough removal of teat cups can result in the reverse upwards flow of milk when air enters, increasing the risk of spreading mastitis-causing bacteria.

Note: routine milking machine tests are designed to check for leaks and are usually performed when the machine is not under load and generally do not take into account current cow teat condition.