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Addressing Teat Condition Problems

Authors:
  • The Dairy Group
Addressing Teat Condition Problems
I. Ohnstad, G.A. Mein, J.R. Baines, M.D. Rasmussen, R. Farnsworth, B. Pocknee,
T.C. Hemling and J.E. Hillerton
Teat Club International (ian.ohnstad@thedairygroup.co.uk)
Introduction
In this paper the collective experience and knowledge of members of the Teat Club International
have been applied to
describing effective treatments, changes in management or changes in machine settings
that appear to provide successful solutions for particular teat condition problems in
commercial herds;
indicating the expected time scale - after the start of a successful treatment or
management change - until improvements in teat condition should become evident;
providing an estimate of the degree of confidence attached to each recommendation or
conclusion.
A selection of teat images, illustrating each of the conditions discussed in this paper, can be
found in the Teat Condition Portfolio, a CD produced by the Institute for Animal Health,
Compton, UK (Hillerton et al. 2001). As an example, the reference (TCCD 2.1) given in the
following paragraph refers to category 2, sub-category 1 in the Portfolio.
Short-term, milking-induced changes in teat condition
Short-term changes are generally regarded as those seen in response to a single milking. Faults in
milking management or milking machines are the primary cause of short-term effects such as:
discoloration - that is, reddened, bluish or purple-coloured teats seen immediately after
milking (TCCD 2.1)
firmness or swelling of the teat (TCCD 2.2) or “ringing” around the upper teat barrel
(TCCD 2.4)
wedging of the teat-end (TCCD 2.3)
degree of openness of the teat orifice (TCCD 2.6.4).
Some specific causes or exacerbating influences on these particular teat conditions are
summarised in Table 1, which is derived mainly from text descriptions in Mein et al. (2001).
Generally the teat takes some hours to recover its full integrity even from good milking
conditions (Neijenhuis et al., 2001). However, improvement in teat condition should be evident
immediately after the milking at which the specific fault or faults have been correctly identified
and fixed. Full rectification may take one or more days and be influenced by milking interval.
Degree of
confidence Comment
High If improvements are not obvious or immediate, then it is likely that the
specific faults have not been identified correctly or they were not corrected
adequately. (Rasmussen et al.,1998; Hillerton et al.,2000)
Table 1. Some of the common primary causes or exacerbating influences on short-term,
machine-induced teat condition.
Teat
colour Swelling
at the
base
Firmness/hardness
of the teat end Open
orifice
Observation Red/blue Ringing Hard Wedge Diameter
Machine factors
High milking vacuum 9 9 9 9
Faulty pulsation 9 9 9
Short D-phase 9 9
Long D-phase
9
Liners - wide bore 9 9 9
- aged 9 9
- high tension 9 9 9
Mouthpiece
- large chamber
9
9
- small lip diameter 9 9
- stiff lip 9 9
Mismatch of liner and teats 9 9 9
Milking management
Long dribble times 9 9 9
Over-milking 9 9 9 9
Teat cup crawling 9
Medium-term, milking-induced or environmentally-induced changes in teat condition
Medium-term changes refer to teat tissue changes that take a few days or weeks to become
noticeable.
Machine-induced hemorrhages of the teat skin (petechial or larger hemorrhages) may take several
days to become evident (see TCCD 2.5). Such vascular damage usually reflects some type of
pulsation failure. If gross or catastrophic, they are often associated with a high milking vacuum or
inadequate liner movement. If the damage is chronic it is more likely to result from prolonged
over-milking (see Table 2).
Some improvement should occur within a few milkings but significant improvement may take up
to 4 weeks after correct identification of the fault and elimination of the cause.
Extreme care must be taken to ensure that vacuum and pulsation issues are considered in
conjunction with cluster position and tube support. Where cluster position is poor, eliminating
vacuum and/or pulsation faults may not provide a complete solution.
Degree of
confidence Comment
Medium-
High Field experience: Field staff are more aware of poor teat condition after
cluster removal. Most problems occur with older style milking equipment
milking higher yielding cows, poorly serviced and maintained equipment,
over-milking or with new installations lacking quality control on the
machine set-up (Hillerton et al., 2000; Hillerton et al., 2002)
Changes in teat skin condition associated with chemical irritation (TCCD 3.8)
When teats were intentionally irritated with a harsh chemical (Fox, 1992), the irritant effect was
maximized after 1-3 days. Progressive healing from the severe teat skin and teat-end damage can
take 3-5 weeks. More typical degrees of irritation resolve in 10-14 days (Rasmussen 2003).
Teat disinfectants more usually induce more significant improvements on teat barrel skin rather
than on teat ends, probably because for skin, the disinfectant and the environment are the major
influences, whereas the milking process has a more significant effect on the teat end. Overall,
both respond in parallel and differ in degree and speed. Skin thickness should not be affected by
teat disinfectants. Aggressive chemicals may remove some epidermal layers. This was shown in a
case study when teats in a UK herd were sprayed unintentionally with a concentrated, low pH,
iodine-based, bulk tank cleaner for three milkings. The burning of teats was severe and took
several weeks for the skin to return to visible normality. Further, many cows in the herd seemed
to become sensitised to iodine products. Successful restoration of teat condition was achieved
using a chlorhexidine formulation with a high concentration of glycerine. It is worth noting that
given the dominant use of iodine as the preferred teat disinfectant, sensitisation to iodine is not
routinely observed.
Aggressive chemicals may also induce a hyperplasia of the epidermis leading to thickened and
scaly skin (TCCD 3.8.0) which will resolve in 7-10 days with use of a milder disinfectant.
The first generation of iodine-based teat disinfectants had a pH 1-2. These still predominate in
some markets e.g. Australia and New Zealand. Their aggressive nature is ameliorated by
emollients. More recently developed iodophor technologies have a pH of 3.5 or more. They
produce little evidence of teat irritation, and sensitivity seems extremely rare. Chlorhexidine
solutions are mild in most cases and unlikely to have an adverse effect on teat skin. Other
technologies such as glutaraldehydes are not recommended as teat disinfectants in any
circumstances.
Improvements in teat skin roughness can be noticed almost immediately after elimination of the
specific cause but reach an end point in improvement in 2-3 weeks
Degree of
confidence Comment
High Field experience. Generally the earlier an adverse reaction is identified, the
more rapid the rectification.
Consistent complete coverage of all teats with disinfectant is required.
Concentrated teat disinfectants must be used at the correct dilution rate and
correctly mixed.
(Rasmussen & Hemling, 2002).
Changes in teat skin condition associated with harsh weather conditions (TCCD 3.6.2).
Changes in teat skin condition occur with harsh or extreme weather conditions, e.g. chapping. If
chaps cover the whole teat then the housing or pasture environment is likely to be a major
influence. If part of the teat is affected, usually the part outside the teat cup, then the milking
parlor conditions contribute. In both cases the effectiveness of teat skin conditioning from good
quality disinfection is limiting.
Degree of
confidence Comments
High Prevention and restoration of poor skin condition is aided by full teat
coverage with disinfectant. A high emollient concentration is important but
may be insufficient with extremely low pH disinfectants (some iodines and
DDBSA) (Hemling 2003). When skin condition has deteriorated
improvements may take 1-2 weeks after removal of the cause.
Weather changes can cause an almost immediate effect on teat skin roughness. Teat skin and end
cracking varies in severity and distribution within 1-2 days under severe winter weather changes,
e.g. in Iowa, where the temperature can change 20Fo between days and on the low temperature
days (0-20oF) the air can be extremely dry (Timms, 2004).
In milder climates, such as in southern Australia, where there can be lots of mud and wind in
winter, with siliceous grasses or grazing on brassicas in winter teat chapping, skin roughness and
dry skin are highly likely.
Table 2. Primary causes or exacerbating influences on medium-term changes in teat
condition induced by milking or environmentally factors.
Teat skin Teat end
Observation Roughness,
Lesions (e.g.,
cracks, chaps)
Haemorrhages Hyperkeratosis
Duration Medium Medium Long
Machine factors
High milking vacuum 9 9
Faulty pulsation 9
Long D-phase 9
Wide bore liners 9
High liner compression 9
High liner tension 9
Milking management
Long dribble times 9
Over-milking 9 9
Chemicals 9 9
Environmental
Cold, wet, windy 9 9
Mud 9
Forage grazed 9
Infectious pathogens 9
Teat-end hyperkeratosis (TCCD 2.6.1)
Excessive keratin at the teat orifice is described by the thickness of any circum-orifice ring and
secondly by the roughness of that ring. The presence and thickness of the ring is infrequent in
heifers before calving and very common in machine milked animals (Sieber and Farnsworth,
1981; Shearn and Hillerton, 1995; Neijenhuis, 1998). Once present it appears to vary little in
response to milking management or other stimuli. Roughness is much more variable. Machine
factors affecting hyperkeratosis are principally vacuum levels, high level of teat compression
during liner closure and machine-on time.
The latter is most influenced by presence and threshold settings levels of automatic cluster
detachers (Shearn and Hillerton., 1995; Rasmussen., 1993) Faulty pulsation is not indicated by
hyperkeratosis.
The amount of hyperkeratosis varies dynamically increasing from calving to peak lactation and
then decreasing towards the end of lactation. It also increases progressively with parity (Shearn
and Hillerton, 1995; Neijenhuis et al, 2002). Teat end hyperkeratosis is often influenced by
seasonal weather conditions (Table 2).
The extent of hyperkeratosis and the degree to which it can be improved is related to teat shape
being worse with long, slender or pointed teats. There may, therefore, may be a genetic influence.
Degree of
confidence Comments
Medium/high In teat conditioning trials a broad range of iodine and chlorine dioxide type
disinfectants and emollient levels did not affect teat ring thickness but did
influence teat ring roughness (Britten, 2004). Noticeable improvements in teat
ring roughness took approximately 4 weeks after elimination of the specific
cause.
Other environmentally-induced teat skin conditions
Photosensitisation (TCCD 3.7)
Lesions due to photosensitization are largely confined to non-pigmented areas of skin exposed to
sunlight and may therefore be evident on the outer surfaces of light-colored teats of affected
cows.
Photosensitization usually occurs when photodynamic agents, mostly derived from plants, are
retained in the bloodstream rather than being excreted at normal rates in the bile.
Photosensitization may also be secondary to liver damage include lantana poisoning and facial
eczema.
Cows with early photosensitization of the teats may be restless and kick at their abdomens
(because the affected areas are very itchy). Affected skin becomes red and edematous but
changes may not be noticed until the top layers of skin die and become hard, dry and leathery, or
sheets of dead skin flake off. In some markets sun blocks, creams or teat disinfectants are
available.
Degree of
confidence Comments
Medium Treatment is by removal of the insults, shade from sun and diet. If liver
damage has occurred this medical problem is the primary issue.
Insect damage (TCCD 3.4)
Insect damage to teats may be caused by blood-sucking flies (most commonly mosquitoes,
midges, sand-flies, black flies or biting flies), nuisance flies or wasps. The cause is usually easy
to observe and pin prick wounds or bites, often with an inflammatory reaction, are obvious on the
teat orifice or barrel. Nuisance flies exacerbate primary damage by abrasion of wounds to create
larger sores.
Teat disinfectants including an insecticide or insect repellent may be available locally and may be
effective when combined with a fly management programme.
Degree of
confidence Comments
Low The trauma is a direct consequence of external influences and may be difficult
to control effectively. Suitable teat disinfectants can assist healing but will not
remove the initial trauma.
Teat condition problems due to infectious agents
Viruses, purulent or necrotizing bacteria, and fungi are responsible for most infectious lesions of
teat skin.
Viral infections vary in severity, infectivity and frequency of occurrence. Generally, they are rare
in dairy industries where good udder hygiene is applied because most are readily controlled by
post-milking teat disinfection and minimising transmission.
Early generation iodine disinfectants, with low pH, have a virucidal activity. Post-milking
disinfectants and emollients reduce the incidence of sores, rough skin, and cracks necessary for
viral penetration and development.
Commonly, multi-use ointment containers are the greatest source of new infections from poor
hygiene. When treating any lesions with ointments, it is important to use only single-use
containers and clean gloves and applicators where necessary.
Pseudocowpox (TCCD 4.1)
Pseudocowpox, a paravaccinia virus causes acute infection in young cows after calving or cows
introduced to a herd that has the virus infection. Spread of infection can be relatively slow.
Immunity is short-lived, lasting four to six months, and infections can be a chronic problem in
some herds. As a consequence, cows in affected herds are likely to suffer repeat infections.
Early lesions are localised, red, edematous and painful. Affected animals resent being milked.
Small, raised, circumscribed lesions (papules) may develop in a couple of days and form rough
dark-red centres. A characteristic ring or ‘horseshoe’ shaped scab usually heals without scarring
in 3-6 weeks.
Milkers may develop localized lesions usually on their hands, i.e. ‘milkers’ nodules’. No specific
treatment exists. Spread of infection can be minimized by milking infected cattle at the end of the
run and wearing gloves.
Degree of
confidence Comments
High Success of treatment depends on consistent complete coverage of teats with a
licensed and effective disinfectant.
Bovine herpes mammillitis (TCCD 4.2)
Two herpes viruses cause mammallitis. The effects range from sero-conversion with no lesions;
cows that become hard to milk showing no lesions; mild lesions that eventually heal; to severe
ulcerative lesions that may result in secondary infections and mastitis. When first noticed, many
animals especially heifers, may be affected. In some herds the problem is on-going with 5-10%
cows permanently affected, in others the number of animals affected and the severity cycles over
a few years. The disease varies seasonally being more likely in colder weather. Transmission
mechanisms are not fully understood. Recrudescence appears more of an issue in herds when the
virus has been present for some time.
Carrier animals may exist, cow-to-cow transmission may occur and milking conditions are
probably involved as heifers succumb soon after calving.
Degree of
confidence Comments
Low Teat disinfectants do not seem to prevent infection but may help teats to heal
and prevent secondary infections. Possibly reducing pre partum edema will
help in heifers if only to limit skin sloughing and necrosis, more common in
heifers. Good milking time hygiene can only be helpful.
Teat warts - papilloma (TCCD 4.4)
Six separate papilloma viruses cause teat warts including the ‘rice grain’ flat white warts (strain
BVP-5), frond-like papillomas that protrude in a ragged fringe of up to one centimetre in length
(strain BVP-6) and fibropapillomas that protrude from the teat surface (strain BVP-l).
Young animals are very susceptible to papilloma viruses, and usually develop immunity soon
after they enter the milking herd. In older cattle, papillomas are usually confined to the udder and
teat. Spread is between animals via teatcup liners and milkers’ hands.
There is a wealth of anecdotal evidence that certain areas are more prone to warts, usually areas
close to low lying river plains and forestation.
Warts can interfere with the function of the liners and can, in some cases, block the teat canal. If
they become damaged, they may be colonised by Staphylococcus aureus, Actinomyces pyogenes
or Streptococcus dysgalactiae.
Degree of
confidence Comments
Medium/high Teat disinfectants do not seem to prevent infection but may help teats to heal
and prevent secondary infections. Possibly reducing pre partum edema will
help in heifers if only to limit skin sloughing and necrosis, more common in
heifers. Good milking time hygiene can only be helpful.
Most warts are self-limiting and disappear within 5-6 months. The frond type can be physically
removed. If there is a major problem in a herd, an autogenous vaccine can be made from wart
tissue from cows in the herd. Type-specificity is high, so vaccines must include all serotypes and
tissue types responsible for the outbreak. The response of the low, flat warts to vaccination is
relatively poor. Teat dipping with a salicylic acid formulation is often used for heifers.
Foot and mouth disease virus (TCCD 4.5)
Common symptoms in cattle are blisters (vesicles) in the mouth and on the tongue and feet,
although blisters on teats and udders are also common. In the UK outbreak of 2001 they were
often the first signs noted by milking staff. Milk yield drops dramatically with the onset of the
disease and the animal is prone to mastitis. Teat blisters and skin erosion caused by FMD are
similar and easily confused with teat trauma caused by milking machines, pseudocowpox, bovine
herpes mammillitis and chemical burns. Veterinary advice must be sought. The disease can be
spread via the milking units, bedding and people.
Although the first signs are blanching (loosely described as whitening or loss of colour) of the
epithelial layer of the teat skin, it is normally the fluid-filled blisters that are first noted by the
milker. These burst by the second day to leave red, raw patches. Rupturing of the blisters is
aggravated by the action of milking. Cows can be difficult to milk due to sensitive teats.
Between days 3 and 7 the lesions become less defined and blood scabs begin to form and
subsequently scar tissue remains. With time this heals, although may still be evident on
examination. Milk yield is often permanently reduced. Many cows will continue to be carriers
of the disease. Secondary infections of the ruptured teat skin can occur, where diseased cattle are
not culled.
Degree of
confidence Comments
Low Although vaccination is an option in many countries, the disease control
strategy is often to use vaccination to contain an outbreak and then to cull
such animals at a later date. Opinion is divided among professionals whether
a culling or vaccination policy is the best option.
Use of emollients will be highly beneficial in healing teat skin, speed
recovery and improve cow comfort. With the large depression in milk yield
following the disease, stopping milking will be an aid to recovery of the teat
skin.
Vesicular stomatitis (TCCD 4.6)
The signs of this viral infection are indistinguishable from those of Foot and Mouth Disease,
although it is less contagious. Vesicular stomatitis is only found within the Americas. It is
normally spread by sand flies and black flies, although it can also be spread by direct contact with
infected animals, by water troughs and feed bunkers contaminated with infected saliva and via
the milking equipment.
In addition to excess salivation and blisters in the mouth and on the tongue, lips and muzzle it is
characterised in cattle by lesions on the teats. Blisters burst within 24 hours of first appearing
and there is a marked drop in milk yield. Milking can be very difficult, due to the erosion of teat
skin, and mastitis is often associated with the teat conditions. It is not uncommon for secondary
infections of the affected teats to occur. The disease is generally not life threatening and animals
recover in around 2 weeks
Degree of
confidence Comments
Medium/high The virus is susceptible to many of the teat disinfectant products used in the
industry including sodium hypochlorite (1%), and iodophors (2%) and their
use with a satisfactory level of emollient will aid recovery of affected teat
skin.
Bacterial infections of teat skin (TCCD 4.8)
Bacteria cause primary lesions or colonise existing lesions caused by machine-induced damage,
environmental factors or viral infections.
Staphylococcus aureus, Streptococcus dysgalactiae and Actinomyces pyogenes are ubiquitous on
the skin of dairy cows. They are a major source of new intramammary infections and clinical
mastitis, in lactating and non-lactating cows. It was shown clearly some 30 years ago that
chapped teats were highly likely to be infected with Staphylococcus aureus or Streptococcus
dysgalactiae, and that such infections were closely associated with high new infection rates and
frequent cases of clinical mastitis (Dodd and Neave, 1970). Even small teat lesions are
significantly associated with sub-clinical mastitis and the risk of mastitis increases as the lesions
approach the teat canal (Agger and Willeberg, 1986).
Disinfectants developed for teat treatment are usually effective at eliminating bacteria from
lesions and often contain emollients to promote skin healing. The requirement to disinfect all
teats of all cows after every milking, as part of mastitis control, is directed at reducing the
exposure of the mammary gland to these organisms and to expedite rapid healing of all lesions.
Blackspot (TCCD 4.8) is the manifestation of a secondary infection of a teat end lesion by the
anaerobe Fusiformis necrophorum. The primary lesion is colonized following poor hygiene. The
resulting scab is pigmented black by the bacteria. The teat orifice may become blocked, leading
to incomplete and very slow milking.
If more than 2 –3% of teats are affected, hygiene should be improved and milking machine
function should be thoroughly checked because blackspot is often associated with short teatcup
liners, failure of pulsation, excessive vacuum or over milking.
The management of the winter housing also has a significant impact with heavy soiling of free
stalls and straw packs increasing the regularity of identification of blackspot.
Degree of
confidence Comments
Medium Management of blackspot in a herd involves:
treating the lesions with hydrogen peroxide or iodine;
using teat disinfection to minimize bacterial infection of lesions; and
• checking the milking machine function.
Fungal infections of teat skin.
Ringworm (TCCD 4.7) is caused by the fungi Trichophyton spp. It occasionally spreads to the
teat. It is very unlikely to be confined to the teats and udder and is easily recognised from the
characteristic grey-white and ash-like skin encrustations. The infection is highly contagious and
may spread to milking staff. Usually herd immunity develops but reoccurrence is typical when
new susceptible animals are introduced or animals are immune-stressed, especially as spores
survive in the environment, especially wooden parts of housing, for several years.
Various drugs and some vaccines are available depending on the market.
Degree of
confidence Comments
Low It is normal for the infection to pass through a herd. Immunity will follow but
not before the majority of animals have become infected. Thorough deep
cleansing may be of some benefit.
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... Teat warts were the most commonly found disease in this study. As teat warts can persist for several months (Ohnstad et al., 2007), the likelihood of detecting them in a cross-sectional study is higher than that of detecting shorter-lasting lesions such as UE. ...
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Recently, Hemling (2014) noted that ‘teat disinfection is the most important second in the milk harvesting process, in terms of milk quality, mastitis control, and cow longevity’. This second refers to the time that it takes a milker to dip a teat in a disinfecting solution during the milking routine, with the major objective of eliminating microorganisms that could compromise the health status of the mammary gland. The investment in time and money in this critical step of the milking process could mean a world of a difference for the farmer’s pocket when considering the high economical costs and the impact on cow longevity of a single mastitis case. This paper aims to summarize and clarify the basic concepts about teat disinfectants components, and provide guidelines for the practical use by the dairy producer.
... Mechanical forces during machine milking affect changes in teat tissue condition Guarín and Ruegg, 2016;Penry et al., 2017b) that are differentiated into long-term, medium-term, and shortterm changes (Mein et al., 2001). Short-term changes represent tissue responses to a single milking and are due to congestion and edema (Hamann and Mein, 1990;Mein et al., 2001;Ohnstad et al., 2007). They have been associated with teat canal openness, penetrability, and thus susceptibility to new IMI Paulrud et al., 2005;Upton et al., 2016) and diminished animal well-being (Hillerton et al., 2002). ...
Article
Machine milking-induced changes in teat tissue condition, such as congestion and edema, have been associated with teat canal openness, penetrability, and thus susceptibility to new intramammary infections and diminished animal well-being. The primary objective of this study was to investigate the association of teat-end shape and machine milking-induced short-term changes in teat tissue condition. Our secondary objective was to study the association of udder-level milking characteristics and short-term changes. Data from 125 Holstein cows were analyzed in a longitudinal prospective cohort study. Cows were housed in freestall pens with sand bedding, fed a total mixed ration, and milked 3 times per day. Teat-end shape was classified into 3 categories: pointed, flat, and round. Udder-level milking characteristics were obtained from electronic on-farm milk meters. Short-term changes in teat tissue condition after machine milking were assessed visually. Multivariable generalized mixed model analysis showed an association between teat-end shape and short-term changes. Compared with teats with round teat-end shape, the odds ratio (95% confidence interval) for short-term changes was 1.68 (0.53–5.31) and 0.03 (0.004–0.19) in teats with pointed and flat teat-end shape, respectively. There was an association between milking characteristics and short-term changes such that higher milk flow rate during the first 15 s of milking decreased the likelihood of short-term changes. The adjusted probability of short-term changes for a milking observation of a mid-lactation cow and an average first 15-s milk flow rate of 0.5 and 1.5 kg/min was 53.0% (42.8–63.8) and 32.9% (15.2–57.3), respectively. Our results suggest that teat-end shape may be one of the risk factors that contribute to machine milking-induced short-term changes. Milking characteristics (e.g., first 15-s milk flow rate) may have the potential as a measure to indirectly monitor teat tissue changes associated with machine milking on a daily basis, though further research is needed to validate this hypothesis and to establish thresholds that could serve as on-farm guidelines.
... Despite this known risk factor, the simple addition of a skin conditioning agent to a teat dip may not independently influence IMI risk to a marked degree. Other factors such as ambient temperature, milking duration, and teat dip pH affect teat skin condition (Ohnstad et al., 2007) perhaps to greater degree. These other factors might mask the potential improvements in teat skin condition and subsequent IMI risk. ...
Article
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Two meta-analyses were conducted using data from peer-reviewed natural exposure (NE) and experimental challenge (EC) teat dip efficacy trials to identify factors influencing the new intramammary infection (IMI) rate. A NE data set containing 16 studies and an EC data set containing 21 studies were created. New IMI rate was calculated based on the percentage of new quarter infections per month (PNQI/mo) for each observation, in both data sets, and used as the dependent variable for model derivation. A linear, mixed-effects model with a random study effect, weighted by number of quarters eligible for infection, was derived for each data set. The final NE model included the effects of experimental design (split herd or split udder), mastitis pathogen group (Staphylococcus aureus, Streptococcus agalactiae, environmental streptococci, gram-negative species, Corynebacterium spp., or coagulase-negative staphylococci), postmilking treatment (iodine, chlorhexidine, linear dodecyl benzene sulfonic acid, chlorine compounds, phenol compounds, or undipped negative controls), and the interaction between mastitis pathogen group and postmilking treatment. Overall, Corynebacterium spp. had the highest new IMI rate (0.0139 ± 0.0018 PNQI/mo), and environmental streptococci and gram-negative species had the lowest (0.0023 ± 0.0022 PNQI/mo). Additionally, trials utilizing a split herd experimental design had a 2-fold higher new IMI rate than trials using a split udder design. The final EC model included the effects of mastitis pathogen (Staph. aureus and Strep. agalactiae), postmilking treatment (iodine, chlorine compounds, “other” active ingredients, or undipped negative controls), geographic region of study (Eastern, Southern, and Pacific Northwest), and the 2-way interactions of region and pathogen group and postmilking treatment and pathogen group. Overall, Staph. aureus and Strep. agalactiae had similar new IMI rates. Quarters dipped postmilking in either iodine (0.0127 ± 0.0099 PNQI/mo), chlorine compounds (0.0258 ± 0.0095 PNQI/mo), or “other” active ingredient teat dips (0.0263 ± 0.0106 PNQI/mo) had lower new IMI rates than undipped quarters (0.0859 ± 0.0087 PNQI/mo). These results indicate that experimental design influences the new IMI rate of teat dip efficacy trials and that using an effective postmilking teat dip has a greater effect on controlling the new Staph. aureus and Strep. agalactiae IMI rate than the teat dip's active ingredient.
... Neijenhuis et al, (2001c) described an internationally recognized system that consists of a four level scale used to classify teat-ends, including, no ring (Score N), smooth or slight ring (Score S), rough ring (Score R), to very rough ring (Score VR), This system for classification of teatend condition is used to identify and resolve problems with the animals, the environment, or the milking machines (Neijenhuis et al., 2001c). Factors that increase the amount of hyperkeratosis include stresses applied to skin when the milking liner collapses on the teat end, excessive linear compression, duration of the milking, milk production level, milking frequency, thresholds applied to automatic cluster removal, humidity and temperature, and teat shape and dimension (Mein et al., 2001; Ohnstad et al., 2007). Increased liner compression is associated with increased development of teat-end hyperkeratosis (Mein and Reinemann, 2009). ...
Thesis
Mastitis is the most frequent and costly infectious disease of dairy cows throughout the world. Mastitis causes decreased milk production, reduced milk quality, decreased cheese yield, increased the cost of treatment, increased labor, and increased culling. Mastitis in the United States causes an estimated loss exceeding $2 billion per year. Control of the disease is based on prevention of new cases, appropriate treatment of infected mammary glands, and culling of clinically affected animals. Prevention is the most effective intervention but requires farms to identify appropriate risk factors. Various risk factors are present at each level of the farm, and within the individual animal, especially in the anatomical characteristics of the udder and teat. Knowledge of these risk factors allows researchers and consultants to plan interventions that will ensure the greatest impact on the disease. During the development of this dissertation, both machine and cow-level aspects of mastitis risk have been reviewed. Among these risk factors are: 1.) the effect of the quarter position (e.g. front versus rear quarters), 2.) development of teat-end hyperkeratosis, 3.) changes in teat dimensions during milking, 4.) peak milk flow rates, and 5.) the effect of teat diameter on increased risk for mastitis. The aim of this dissertation was to evaluate milking management and teat related risk factors that predispose the cows to develop mastitis. Chapter I is a comprehensive literature review about mastitis and some anatomical and farm management risk factors for this disease. Chapter II contains a study about pre- and post-milking anatomical characteristics of teats and their associations with risk of clinical mastitis. Chapter III covers the associations of anatomical characteristics of the teats with quarter level somatic cell counts. Chapter IV presents the results of an experiment conducted to evaluate anatomical characteristics of teats and pre-milking bacterial counts of teat skin of primiparous cows exposed to different type of beddings.
... Maintaining healthy teat skin reduces bacterial colonization and possible IMI. Practical troubleshooting guidelines to score teat condition have been published by the NMC (Ohnstad et al., 2007). Irritation to the cow or the user should be addressed by the developer of the product during early stages of development. ...
Article
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The objective of this study was to complete a positive-control, natural exposure, noninferiority design field study to test the efficacy of a novel glycolic acid-based postmilking teat disinfectant as compared with a previously proven iodine-based postmilking teat disinfectant (positive control). The primary outcome of interest was the effect of treatment on incidence of new intramammary infections. Secondary outcomes included the effect of treatment on prevalence of infection, somatic cell count, and teat condition. After blocking by parity, approximately 300 early- to mid-lactation cows on a large Wisconsin dairy farm were randomly assigned to 1 of 2 groups. For a 12-wk period between May and August 2014, the 2 groups were dipped after each milking with either the experimental (EX) or positive control (PC) product. Individual quarters were sampled to establish bacteriological infection status at the beginning of the study, and every 2 wk thereafter, by use of a 2-stage process evaluating somatic cell count (SCC), and then culturing milk samples only when SCC exceeded a parity-specific threshold. Teat condition scoring was completed at the beginning of the study and on wk 4, 8, and 12. Mixed logistic regression was used to evaluate the effect of treatment on dichotomous outcome measures including the odds of acquiring a new infection during a given 2-wk sampling interval (incidence), the odds for presence of infection at sampling (prevalence), and odds for a normal teat skin condition score. Mixed linear regression was used to evaluate the effect of treatment on somatic cell count. For the noninferiority analysis, the upper bound of the 95% confidence interval for the difference in new infection rate between the 2 treatments (EX-PC), had to be to the left of the critical value d (0.035) to conclude that EX was noninferior relative to PC with respect to risk for new infections. Results showed that the incidence of new infections was not different for quarters dipped with EX (3.2%) as compared with PC (4.2%). Similarly, the prevalence of infection tended to be lower for quarters dipped with EX (3.92%) as compared with PC (5.03%). No overall difference was found between treatments when evaluating somatic cell count measures and teat condition scores. Because the upper bound of the 95% confidence interval of the new IMI rate difference was smaller than the predefined noninferiority limit, it was concluded that the experimental product was not inferior compared with the positive control. As such, the glycolic acid-based teat disinfectant evaluated in this study can be considered an effective postmilking teat disinfectant, as well as safe, in so far as the product was not irritating to teat skin and did not negatively affect skin condition measures, as compared with the positive control group.
... Each of these categories has different causal factors and some compromise is needed to achieve a reasonable degree of gentleness in all categories. A new paper (Ohnstadt et al. 2007) on teat condition problems provides a basis for determining changes to milking management or the milking machine to address these aspects. ...
Conference Paper
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Machine milking, like a good marriage, is an exercise in compromise. Obsession with one goal at the expense of the others is seldom the optimal solution. The main goals of machine milking are to remove the available milk from each cow's udder quickly and completely, without slipping or falling, with minimum discomfort to the cow and minimum damage to her teats. Balancing these goals requires compromise because: • Maximizing milking speed often results in less complete and/or less gentle milking. • Maximizing completeness of milking generally results in slower and less gentle milking. • Maximizing gentleness results in slower milking and may result in less complete milking. How quickly, how gently, and how completely should we aim to milk each cow and how should we balance these goals? Basic concepts and relevant research results are outlined in this paper to help managers of modern milking parlours achieve a balanced approach to milking and make the most of the machine-on time. How quickly can we expect to milk each cow? Milk flow-rate curves of individual cow milkings provide a good starting point for understanding the "machine-on" part of the milk harvesting process (eg, Bruckmaier & Hilger, 2001; Schukken et al. 2005). Two sets of milk flow-rate curves from Bruckmaier & Hilger (2001) are reproduced as Figures 1 and 2 below. These curves illustrate several interesting and important lessons. All but one of the six curves in Figure 1 show the undesirable but common characteristic of delayed milk ejection, ranging from about 0.8 to 1.8 min after clusters were first attached. In this particular study, delayed milk letdown was due to a combination of reduced milk yield and inadequate pre-milking stimulation. The results support Bruckmaier's conclusion that the time required for milk ejection is closely -and inversely -related to the amount of milk in an udder. Delayed milk ejection problems also occur frequently when cows are unsettled at -or shortly before -the time of cluster attachment, or when the timing of cluster attachment does not coincide with the time of milk ejection. All of these causes of delayed milk ejection and low milk flow at the start of milking have everything to do with milking management and nothing to do with the milking machine.
Conference Paper
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Milking-parlour technology and milking problems were analysed on the basis of farm-structure data and user evaluations furnished by a survey of Swiss dairy farmers. The number of modern milking parlours for loose-housing systems rose steadily in the past. Most common were 30° herringbone and tandem milking parlours. Depending on parlour type, the percentage of farms with milking problems ranged between 9% and 28%, with these farms housing more dairy cows with higher milk yield in older barns. By contrast, milking-parlour performance did not differ appreciably between farms with and without milking prob-lems. Swing-over, tandem and autotandem milking parlours were rated considerably better in terms of workplace comfort than the 30° herringbone milking parlours. Satisfaction levels for all types of milking parlour were good, although farmers reported a lower overall-satisfaction score for 30° herringbone, 50° herringbone, side-by-side, swing-over and tandem milking par-lours when milking problems arose. In summary, the survey shows that although the various milking parlours were rated positively by farmers, the percentage of farms with milking problems can nonetheless be characterised as very high. It can thus be seen that high milk yields and high milking parlour performance cannot necessarily be adduced as proof of optimal milking conditions.
Article
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The purpose of these experiments was to (1) assess differences in mastitis pathogen strain sensitivities to teat disinfectants (teat dips), and (2) determine the optimum time for premilking teat dips to remain in contact with teat skin to reduce pathogen loads on teat skin. Two experiments were conducted using the excised teat model. In experiment 1, the differences in mastitis pathogen strain sensitivities to 4 commercially available dips (dip A: 1% H2O2; dip B: 1% chlorine dioxide; dip C: 1% iodophor; and dip D: 0.5% iodophor) were evaluated. Four strains of 11 common mastitis pathogens (Staphylococcus aureus, Streptococcus agalactiae, Mycoplasma bovis, Streptococcus dysgalactiae, Streptococcus uberis, Escherichia coli, Staphylococcus chromogenes, Staphylococcus epidermidis, Staphylococcus hyicus, Staphylococcus xylosus, and Staphylococcus haemolyticus) were tested. In experiment 2, the percentage log reduction of mastitis pathogens (Escherichia coli, Streptococcus uberis, Streptococcus dysgalactiae, Klebsiella species, Staphylococcus chromogenes, Staphylococcus haemolyticus, Staphylococcus xylosus, and Staphylococcus epidermidis) on teat skin with 3 commercially available teat dips: dip A; dip D; and dip E: 0.25% iodophor, using dip contact times of 15, 30, and 45 s, was evaluated. Experiment 1 results indicated significant differences in strain sensitivities to dips within pathogen species: Staphylococcus aureus, Staphylococcus chromogenes, and Streptococcus uberis. Species differences were also found where Mycoplasma bovis (97.9% log reduction) was the most sensitive to tested teat dips and Staphylococcus haemolyticus (71.4% log reduction) the most resistant. Experiment 2 results indicated that contact times of 30 and 45 s were equally effective in reducing recovered bacteria for dips D and E and were also significantly more effective than a 15-s contact time. No differences were seen in recovered bacteria between tested contact times after treatment with dip A. It can be concluded that different mastitis pathogen species and strains within species may possess different sensitivities to teat dips, which may have implications in selection of teat dips on dairies. Furthermore, a 30-s premilking dip contact time for iodophors and 15 s for H2O2 dips may be optimal in reducing pathogen load in the shortest amount of time. A reduction in premilking teat dip contact time may improve milking parlor efficiency. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Article
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Classification of bovine teat condition can be used to assess the effects of milking management, milking equipment or environment on teat tissue and the risk of new intramammary infections. Veterinarians and others require a simple and reliable method for evaluating teat health in dairy herds. Hillerton et al. (2000) proposed simple methods for quantifying short- or medium-term effects of machine milking on teats. Such changes are easily recognizable immediately after cluster removal. The purposes of this paper, by an informal discussion group of researchers and udder health advisers self-styled as the "Teat Club International", are: 1) to review non-infectious factors affecting short- or medium-term changes in teats; 2) to propose a simple protocol for systematic evaluation of teats in commercial dairies; 3) to propose guidelines for interpretation of these observations. The full version of this paper with many references, example pictures and sample recording charts is posted on the UW-Madison Milk Quality website (http://www.uwex.edu/milkquality/ ). Other companion papers in the "Teat Club" series in this AABP/NMC Conference Proceedings discuss infectious factors (Hillerton et al.), data collection and analysis (Reinemann et al.), and the relationship between teat-end hyperkeratosis and mastitis (Neijenhuis et al.).
Article
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Teat end and skin condition is an important property that is affected by a variety of factors including the milking machine, weather, bedding, and physiological status. Teat disinfection is employed primarily to aid in the prevention of new infections but is also an opportunity to improve teat condition. Teat condition or teat tolerance studies are a required part of medicinal product registrations. The aim of this paper is to discuss the formulation variables that may positively or adversely impact teat condition and to review some of the available clinical data. This information should help dairy producers and advisors in making judgements about product selection and product claims relating to teat conditioning. Products are referred to as teat dips. This is used as a catch#all phrase to include teat disinfectants, some of which may be sprayed. BACKGROUND Preservation of healthy teat skin is important in maintaining a natural defense against infection. Improvement or maintenance of teat condition is important to the dairy producer because it can affect the bacterial colonization of skin, milk let#down, milk#out time, milking speed and parlor through put. Fox (6) has shown a correlation between teat skin condition and colonization of skin by Staphylococcus aureus . It is accepted that rough or chapped skin will provide more places for bacteria to attach and survive. An impact on udder health and mastitis can be anticipated. McKinzie and Hemling (11) showed an impact of teat skin condition on milk yield and milk out time. In this study, teats were intentionally chapped then dipped at each milking with an emollient iodine post#dip. Milking was done in a Double 6 (12 unit) DeLaval herringbone parlor with automatic cluster removal. Teat condition was evaluated daily against milk production (seven day rolling total) and milk#out time (Figures 1 and 2). When teats had the worst teat condition, milk yield was lowest and milk#out time was highest. As teat condition improved, milk yield increased and milk#out time decreased. Decreased milking time and increased milk yield provide additional economic incentive to maintain healthy teat condition.
Article
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The effect of a switch level of 200 or 400 g/min for automatic cluster removers on milking performance and udder health was measured with 71 first lactation cows in their first 36 weeks of lactation and with 64 older cows in their first 12 weeks of lactation. Early removal of the milking unit decreased machine-on time by 0.5 min, increased average milk flow rate slightly, improved teat condition significantly and reduced the change in teat end thickness during milking of first lactation cows. Early removal of the milking unit did not affect milk yield or composition, and the incidence and prevalence of subclinical mastitis were the same in the two groups. Fewer older cows developed clinical mastitis in the group switched at 400 g/min, but this was not significant. It is concluded that the milking unit can be detached at a milk flow rate of 400 instead of 200 g/min without having a negative influence on milk yield. Machine-on time is shortened and teat condition improved and udder health does not seem to be affected.
Article
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Teat orifice hyperkeratosis, a commonly observed condition in dairy cows, has been considered a consequence of machine milking and the degree of hyperkeratosis may be increased by a poor milking system. A fully illustrated technique is described which uses a scoring system from 0 for a perfect orifice to 5 for an orifice significantly enlarged with extensively protruding fronds of teat duct keratin. A range of scores found in 25 commercial dairy herds is presented. The scores have been averaged for each cow and the markedly skewed distribution corrected by a square root transformation. This scoring procedure allows comparative measures of hyperkeratosis within and between herds. An 8-fold difference (0.17-1.31) in herd average score was found. Within all herds the score increased with lactational age of the animals and peaked, for any lactation, some 3-4 months post partum, declining as the animals dried off. There was no significant relationship between mean somatic cell count and degree of hyperkeratosis at the herd level. This implies that such chronic pathological changes are unlikely to be related to the level of intramammary infection. It appeared that some hyperkeratosis is an obvious and probably natural response to milking and occurs in a significant proportion of animals in all herds although often only to a slight degree. Much more hyperkeratosis may be a measure of the performance and management of the herd. The genetic influence is unknown. Higher yielding cows will score higher as they milk for longer, but generally high scores may reflect consistent and possibly considerable overmilking. Hyperkeratosis may be an indicator of the quality of management and show the level of attention being paid to the welfare of the herd.
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The effects of milking cows with two different liners were measured for a period of 8 months with 115 Danish Holstein cows divided into two groups. Group H and L animals were milked with liners with mouthpiece cavity heights of 30 and 18 mm respectively (other dimensions also differed between the two liners). Average teat lengths of first lactation cows were 45 and 40 mm for front and rear teats. Older cows had teats approximately 10 mm longer. There was no difference in milk yield or milk flow rates between the two groups. Average machine-on time was shorter for group L, and first lactation cows of group L were less restive. The frequency of red and blue discoloured teats immediately after milking was higher for group H, and teat length increased on average 5 mm during lactation with no increase for group L. The small overall differences in udder health between the two groups were not significant. Udder health was better for first lactation cows of group L, even though liners of group L slipped more often and cows with recorded liner slip had poorer udder health. We conclude that special attention should be given to first lactation cows when liner type is selected for a herd. We propose that breeding programmes should ensure that teat length is kept above 50 mm.
Article
The abilities of common postmilking teat disinfectant solutions and a teat skin ointment to retard Staphylococcus aureus colonization and promote healing of chapped skin were studied. Ten Holstein cows, free of S. aureus intramammary infections and mammary epidermal colonization, were used. All teats were experimentally chapped with 1N sodium hydroxide and dipped in S. aureus broth culture of 5 x 10(6) cfu/ml after three consecutive milkings. Postmilking teat disinfectant treatments were applied, starting after the second application of S. aureus broth culture, and were continued for the next 19 milkings. Quarters of each cow received one of the following postmilking teat treatments: 1% iodine plus 10% glycerin solution; .5% chlorhexidine plus 4.87% glycerin solution; 1% chlorhexidine ointment; and no postmilking treatment. After milking and before treatment application, samples of skin swabbings of the teat end and teat side and samples of milk were collected. Daily teat skin chapping visual scores were made to assess chapping and healing. Teat skin chapping decreased with time, and the decline was similar among treatments. The concentration of S. aureus recovered from teat skin swabbing solutions decreased over time. Staphylococcus aureus were recovered at significantly lower concentrations from swabbing solutions of teats that were dipped with iodine and chlorhexidine solutions as compared with untreated teats. Staphylococcus aureus was in marginally higher concentrations on ointment-treated teats than on dipped teats. Results indicate the importance of using postmilking teat dips on chapped teats and suggest no advantage in applying a disinfectant ointment to chapped teats to reduce S. aureus colonization and improve skin healing.
Article
Even small teat lesions are significantly associated with subclinical mastitis and the risk of mastitis increases as the lesions approach the teat canal. Analyses show that at least 7% of cases of subclinic mastitis would have been avoided if no teat lesions had occurred in the herd in question. Analyses also indicate that the risk of mastitis in a quarter increases by about 50% across a 10 months follow-up period (equivalent to one lactation period) after the teat has been injured.
Article
A field study that involved 22 herds of dairy cattle (1,055 lactating cows, 126 nonlactating cows, and 32 heifers) was done to determine the prevalence of teat-end lesions and their relationship to intramammary infection. Teats were grouped into 4 general categories: normal teat ends; smooth, chronic ring lesions; rough, chronic ring lesions; and acute teat-end lesions. Only 15.8% of the teats could be classified as normal; 63.1% had smooth, chronic ring lesions, 13.8% had rough, chronic ring lesions, 0.3% had acute teat-end lesions, and 7% could not be classified. The level of intramammary infection was determined for each teat-end classification. Milk samples were obtained from each mammary gland of all lactating cows. The prevalence of intramammary infection in glands with normal teat ends and in those with chronic ring lesions was not significantly different. Glands with acute teat-end lesions and those in cows in which the teat had been traumatized or leaked milk had higher rates of infection.
Article
To examine the development of teat end callosity thickness and roughness in early lactation and to quantify cow factors of interest, a system to classify teat end condition was developed. A distinction was made between rough and smooth rings around the teat orifice. In addition, a classification of the degree of callosity was developed. Kappa coefficients for the repeatability of scoring by this classification system by different workers were 0.71 for teat end callosity thickness and 0.86 for teat end callosity roughness. The teat end callosity classification system was used for a longitudinal study with 40 cows during the first 14 wk of lactation. Models were built to predict teat end callosity thickness and roughness, machine-on time, and milk yield. For the response variables, teat end callosity thickness, machine-on time, and milk yield, the consecutive measurements appeared to follow a lactation curve model with a subject-specific general slope and intercept. Teat end callosity increased rapidly the first 8 wk. Cow factors such as days in milk, parity, machine-on time, and teat end shape were associated with the degree of teat end callosity, and the probability of the callosity ring to become rough. Teat end callosity thickness did not decrease within the 14-wk trial period for most teats. Pointed or round teat ends showed more callus than inverted teat ends. Longer machine-on time resulted in a higher probability of the callosity ring to become rough. Rear teats showed less callosity than front teats in this study.
Article
Recovery time of teat tissue after milking was determined by ultrasonographic scanning. Teat-canal length, teat-end width, teat-wall thickness, and teat-cistern width of 18 cows varying in parity and lactation stage were measured in duplicate before and directly after milking and every hour for 8 h. The ratio between teat-wall thickness and teat-cistern width was calculated. The effects of time after milking and teat position on the teat parameters were estimated using REML models. The mean differences of ultrasound measurements of teat-end width and teat-canal length between duplicate measurements were 3.6 and 8.2%, and between d 4.4 and 7.8%, respectively. Teat-wall thickness and teat-cistern width were more variable (15.3 and 22% between duplicates, and 13.6 and 19.9% between days, respectively). Teat recovery after milking took a considerable amount of time: teat-wall thickness, 6 h; teat-end width, >8 h; teat-canal length, >8 h; teat-cistern width for rear teats, 3 h, and front teat 8 h, and the ratio of teat-wall thickness and teat-cistern width, 6 h. Ultrasonographic scanning of teat parameters was a useful tool to study teat changes caused by milking. Teat recovery took more time than expected, which makes caution necessary when increasing the milking frequency.