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Home , Mastitis, Udder

AS1129 (Revised) Control Programs Bovine Mastitis and Milking Management J. W. Schroeder, Extension Specialist

astitis complex; no simple solutions are Mavailable for its control. Some aspects are well- understood and documented in the scientific literature. Others are controversial, and opinions often are presented as facts. The information and interpretations presented here represent the best judgments accepted by the National Mastitis Council. To simplify understanding of mastitis, you’ll need to consider that three major factors are involved in this Figure 1 disease: the microorganisms that cause it, the cow as host and the environment, which Cows contract infection to reduce this exposure and can influence the cow and the at different ages and stages of enhance resistance to udder microorganisms. (Figure 1) the lactation cycle. Cows also disease. More than 100 different vary in their ability to overcome Practical measures are microorganisms can cause an infection once it has been available to maintain common mastitis, and these vary greatly established. Therefore, the forms of mastitis at relatively in the route by which they reach cow plays an active role in the low and acceptable levels in the cow and the nature of the development of mastitis. the majority of herds. While disease they cause. The cows’ environment continued research is needed to influences the numbers and control the less common forms types of bacteria they are of intramammary infection, exposed to and their ability to herd problems are often the resist these microorganisms. result of failure to apply the However, through appropriate proven mastitis-control practices management practices, the consistently and to consider all North Dakota State University environment can be controlled aspects of the disease problem. Fargo, North Dakota Revised and reprinted July 2012 Definitions Mastitis — of the caused by microorganisms, usually bacteria, that invade the udder, multiply and produce toxins that are harmful to the mammary gland. Clinical Mastitis — visible signs of mastitis, which include: Economic Loss Mild signs — flakes or clots in the , may have slight If we assume the same milk swelling of infected quarter. price and this value is multiplied Severe signs — secretion abnormal; hot, swollen quarter or by the total number of milking udder; cow may have a , rapid pulse, loss of appetite, cows (9 million head), the total dehydration and depression; death may occur. annual cost of mastitis is about $1.8 billion. This is approximately Subclinical Mastitis — no visible signs of the disease: 10 percent of the total value The somatic cell count (SCC) of the milk will be elevated. of farm milk sales, and about Bacteriological culturing of milk will detect bacteria in the two-thirds of this loss is due milk. to reduced milk production in Clinical mastitis causes the greatest financial loss to dairy subclinically infected cows. farmers through lowered milk production The average production For every clinical case of mastitis, 15 to 40 subclinical loss per lactation for one cases will occur. infected quarter is about 1,600 Somatic Cell Count (SCC) — the number of leukocytes or pounds. Other losses are due white blood cells per milliliter of milk. to discarded abnormal milk Normal milk will have less than 200,000 cells per milliliter. and withheld milk from cows An elevated SCC is an indication of inflammation in the treated with , costs of udder. early replacement of affected cows, reduced sale value of The bulk tank SCC gives an indication of the level of culled cows, costs of drugs subclinical mastitis and the loss of milk production in a herd due to mastitis. and veterinary services, and increased labor costs. The estimated costs of these factors are shown in Table 1. Losses to mastitis are estimated at more than $200 per cow These estimates do not annually. The various contributors to direct mastitis losses per include additional costs arising cow are listed in Table 1. from mastitis-associated problems related to antibiotic residues in foods, Table 1. Estimated annual losses due to mastitis.1 milk quality control, dairy manufacturing, nutritional Loss per Cow Percent of Total Source of Loss ($) (%) quality of milk, degrading of milk supplies due to high Decreased milk 140 70 bacteria or somatic cell counts, Discarded milk 20 10 and interference with genetic Replacement cost 16 8 improvement of dairy animals. Decreased sale value 10 5 Drug therapy 8 4 Veterinary service 4 2 Extra labor 2 1 TOTAL $200 100.0 2 Table 3. Estimated annual savings from an effective mastitis control program.

National Mastitis Council Study (Table 1): Production per cow (+1,050 lb @ $12 cwt) $126.00 Clinical mastitis reduced 40% Discarded milk $24 x 40% 10.00 Economics of Total Return $136.00 Mastitis Control Mastitis Control Costs (per cow annually) When analyzing the cost of dip $10.00 Dry-cow medication $4.00 mastitis control, first consider Paper towels $10.00 the cost in lost production. Total Cost $24.00 The bulk tank SCC is a good Net Return to mastitis control (per cow annually) $112.00 place to start. Table 2 estimates A web-based tool will be available to calculate your costs at: expected losses and prevalence www.google.com/url?sa=t&rct=j&q=estimated%20annual%20losses%20due%20to%20mastitis&source=web&c d=11&ved=0CEgQFjAAOAo&url=http%3A%2F%2Fwww.ansci.umn.edu%2Fdairy%2FQuality_Counts_2012 of infection for elevated bulk tank %2Fspreadsheets%2FS-MP-3_Losses_due_to_mastitis-Fetrow2011.xlsx&ei=qgPNT9KIIqPz0gHU_c3SDg&us SCCs. g=AFQjCNHIr0ivY2heh9s7PcDM_GiZktJgjw Consider as well the possible savings when mastitis is managed effectively. The value Effects on Milk Production, of increased milk sales from Composition and Quality reduced mastitis more than Mastitis reduces milk yield and alters milk composition. The magnitude offsets the costs of an effective of these changes in individual cows varies with the severity and control program. (Table 3) duration of the infection and the causative microorganisms. Mastitis almost always is caused by bacteria. These microorganisms produce toxins that can directly damage milk- producing tissue of the mammary gland, and the presence of bacteria Table 2. Estimated infection initiates inflammation within the mammary tissue in an attempt to prevalence and losses in milk eliminate the invading microorganisms. production associated with The inflammation contributes to decreased milk production and is elevated bulk tank SCC. primarily responsible for the compositional changes observed in milk from infected quarters and cows. In general, compositional changes Bulk Tank involve an increase in blood components in milk and a decrease in SCC Percent Percent Percent (1,000s / ml) Infected Infection Production normal milk constituents. in Herd Quarters Level Loss* Production 200 6 4 0 The Dairy Herd Improvement Association (DHIA) has adopted an 500 16 11 6 SCC scoring system that divides the SCC of composite milk into 10 1,000 32 21 18 categories from 0 to 9 known as linear scores. The DHIA programs 1,500 48 32 29 determine the SCC on each milking cow each month and report *Infection level (cows) is based on the the SCC or the linear score. Linear scores can be used to estimate assumption that the average infected cow is infected in 1½ quarters. production losses, but the average linear score for the lactation most **Production loss calculated as a percent of accurately reflects reduced milk yield. Cows with higher lactation production expected at 200,000 cells/ml. Source: Current Concepts of Bovine Mastitis. average SCC scores produce less milk (Table 4). National Mastitis Council, 1996. Production losses in older cows are about double those of first- lactation cows. Determining the exact amount of milk lost at a specific SCC or linear score or for any one cow is not possible. However, the fact remains that elevated SCCs result in major losses to dairy producers, and elevated an SCC is almost always due to the presence of intramammary infection. 3 Composition Table 4. Somatic cell counts as they relate Changes in milk composition to estimated milk losses. accompany the increase in Estimated SCC following infection of Lactation Milk the mammary gland. Table 5 Average Somatic Production Linear Cell Milk Loss Per compares the composition of SCC CMT WMT Count Loss Cow/Year* normal, low-SCC milk with # Score (Score) (mm) (cells/ml) (%) (lb) milk having a high SCC. These 2 Negative --- 50,000 ------comparisons frequently are 3 Negative 2 100,000 3 -400 made between high- and low- 4 5 200,000 6 -800 SCC milk from opposite quarters Trace 8 300,000 7 -1,000 of the same cow to reduce cow- 5 10 400,000 8 -1,200 to-cow variation. Elevated SCCs 12 500,000 9 -1,300 are associated with a decrease 1 14 600,000 10 -1,400 in the content of lactose and fat 16 700,000 -1,500 in milk because of a reduced 6 18 800,000 11 -1,600 ability of the mammary gland 20 900,000 -1,650 to produce these components. 21 1,000,000 12 -1,700 Some studies have shown no <2 24 1,200,000 >12 -1,700 change in fat percentage, yet 7 29 1,600,000 -2,000 total fat production declines with *Based on 14,000- to 15,000-lb average/cow/year, lasted in >2. the decrease in milk production. # Linear score calculation from SCC. Example: SCC = 200,000/ml. Although the total protein CMT Interpretation: Negative - Mixture remains liquid with no evidence of the formation of a precipitate. content may change very Trace - A slight precipitate or small flakes form and then disappear. little as a result of subclinical 1 (weak positive) - A distinct precipitate forms. 2 (distinct positive) - The mixture thickens immediately with some gel formation. mastitis, changes in the types of Source: Dairy Herd Improvement Association and Philpot. proteins present are marked and significant. The major milk protein Linear score calculation from the SCC. is casein. This protein has high nutritional qualities and Example: SCC = 200 (200,000/ml) is very important in cheese 1. Divide the reported SCC by 100.* 200/100 = 2 manufacturing. The casein 2. Determine the natural log (In). In 2 = .693147 content of milk with a high 3. Divide this value by .693147. .693147/.693147 = 1 SCC is reduced, but lower- 4. Add “3” to the result. 1 + 3 = 4 linear score quality whey proteins increase *If SCC is expressed as 1,000s of cells/ml, divide by 100,000: in concentration, resulting in a (200,000/ 100,000) = 2. similar total protein content. The lower-quality whey proteins are blood serum proteins such as serum albumin, immunoglobulins and transferrin, which increase in milk as a result of the destruction of membranes that normally prevent blood serum proteins from entering milk. 4 Sodium and chloride with herd milk at 400,000 cells/ big dividends to producers, as increase in high-SCC milk due ml. A variety of dairy products, shown in Table 6. For example, to the increased passage of including cheeses, powdered a 100-cow herd averaging 50 these minerals from blood into milk, fermented products pounds of milk per cow per milk. Potassium, normally the and fluid milk, are affected. day and receiving a $0.25 per predominant mineral in milk, Progressive milk plants pay on hundredweight premium would declines due to its passage milk quality for obvious reasons, get $375 more per month in milk out of milk to lymph between but quality premiums also pay receipts. damaged secretory cells. Most of the calcium in milk is associated with casein, and disruption of casein synthesis results in Table 5. Changes in milk composition associated 1 reduced calcium levels in milk with an elevated SCC. from mastitic cows. These Normal Milk With Percentage alterations in mineral content Constituent Milk High SCC of Normal affect the pH and conductivity ------% ------of milk. The pH of normal milk is Solids-not-fat 8.9 8.8 99 generally about 6.6, but it may Fat 3.5 3.2 91 increase to 6.9 or higher in milk Lactose 4.9 4.4 90 Total protein 3.61 3.56 99 from mastitic quarters. Total casein 2.8 2.3 82 Other important Whey protein .8 1.3 162 compositional changes include Serum albumin .02 .07 350 increases in enzymes originating .02 .10 500 from damaged mammary tissue, Immunoglobulins .10 .60 600 the blood stream or milk somatic Sodium .057 .105 184 Chloride .091 .147 161 cells. Many of these enzymes Potassium .173 .157 91 negatively impact milk quality. An Calcium .12 .04 33 increase in the enzyme lipase 1Example of compositional changes found in various studies. can raise the content of free fatty acids, which produce off-flavors in milk from mastitic cows. Table 6. Dollar return per month in a 100-cow herd with An additional example is quality premiums of 10 to 50 cents/cwt and average of the enzyme plasmin, which 30 to 70 pounds of milk/cow/day. may double in concentration in high-SCC milk. Plasmin Premium attacks casein and can reduce Per Cwt Quality Premium Return Per 100 Milk Cows Per Month (30 days the casein content markedly, resulting in lower yields of $0.50 $450 $600 $750 $900 $1,050 $0.45 $405 $540 $675 $810 $945 cheese and other manufactured $0.40 $360 $480 $600 $720 $840 products and off-flavors in milk. $0.35 $315 $420 $525 $630 $735 Quality $0.30 $270 $360 $450 $540 $630 $0.25 $225 $300 $375 $450 $525 Mastitis not only reduces dairy $0.20 $180 $240 $300 $360 $420 producer profits but also results $0.15 $135 $180 $225 $270 $315 in important and costly losses to $0.10 $90 $120 $150 $180 $210 processors due to poor-quality Average lb. milk. Reduced quality is detected Milk/cow/day 30 40 50 60 70 Source: W.L. Crist, et al. Mastitis and Its Control. Univ. of Kentucky. 5 Development If the herd size is 75 cows may be harboring bacteria that is Somatic cell programs offered and the SCC score is 800,000, causing serious contamination. If by the Dairy Herd Improvement the estimated loss in milk the older animals are presenting Association (DHIA) provide a production is 120,000 pounds the problem, perhaps: 1) cows tool to monitor the herd and per year. With a milk price of are not being dry-treated, 2) individual mammary health $18 per hundredweight, this lost housing and dry lots need to be status. The programs offer a way milk amounts to a gross income cleaned or 3) calving stalls need to identify clinical or subclinical of $21,600 per year. Not only to be cleaned and disinfected. mastitis so associated milk are you losing income from the You normally can expect the losses can be calculated and/ sale of milk, but you also may older animals to have slightly or measures initiated to correct be losing a premium for not higher SCC scores than heifers. selling high-quality milk, as well the cause of the somatic cell Weighted Herd Average by as income from other mastitis- count (SCC) rise. Increased Sample Day SCCs have been associated related losses. This listing shows the with decreased milk and fat An excellent way to monitor average SCC for your herd production. These losses occur a herd’s SCC score and identify weighted by the amount of even with low SCC readings of potential problem cows and milk each cow produced. This 200,000 cells/ml and below. The management practices is to report shows a rolling six- estimated milk lost for varying enroll in the DHIA-SCC testing month average on your herd’s SCC scores is shown in Table 7. program. This program enables SCC level. Use this information the producer to monitor not only to monitor any management each individual cow’s SCC level, changes made during the last but it also helps in uncovering six months. It also may indicate potential herd management whether the herd’s SCC is being Table 7. Milk production problems. An SCC report is affected by factors of which you losses for various SCC mailed monthly to each producer are not aware. This report also scores. enrolled in the program. The shows if SCC scores increase report has seven components. SCC Pounds/ Pounds/ during certain seasons of the (000s/ml) day lactation Lactation Averages year. If you have a marked 50 0 0 The report stratifies the increase for a given season, 100 1.5 400 average SCC score for three examine the facilities to see if 200 3.0 800 lactation groupings: 1, 2, 3 you have excess moisture in 400 4.5 1,200 and greater. This part of the certain areas, poor sanitation, 800 6.0 1,600 report shows if a problem is lack of shade or other potential 1,600 7.5 2,000 occurring with animals in a problems that should be avoided 3,200 9.0 2,400 certain lactation. If heifers have a or corrected before next year. 6,400 10.5 2,800 serious SCC problem, the heifer- rearing facilities may be dirty or wet, or lack adequate ventilation, or the freshening area for heifers

6 SCC Summary Linear Score Individual Animal Report This gives a distribution of This section lists your SCC The DHIA lists the SCC the number of cows regardless score in a linear form. To provide scores on all cows for the last six of lactation number that fall into more uniform SCC reporting, months. This is an excellent way five SCC levels below 100,000 the Daily Herd Improvement to monitor to spot those to above 800,000 cells. This Association has adopted a animals with chronic problems. immediately lets you know where uniform scoring method called If a cow always has a high SCC your cattle rank. This section the linear score. The linear score, culture her milk to see if also allows you to compare score divides the somatic cell a particular pathogen is causing your herd with the average of all count into 10 categories from 0 the problem. Once a specific herds in the midstate processing through 9. pathogen is identified, establish area. Remember, one or two and follow your ’s Animals Over 400,000 Cell cows can influence your herd’s treatment program. The DHIA- Count SCC score greatly, so be certain SCC report can be a valuable All animals that have cell to look at this summary to aid in aid in identifying some of the counts in excess of 400,000 interpreting your overall score. major causes of mastitis. The are listed under this section. common causes of mastitis that Days in Milk SCC Average These cows should have quarter cause high cell counts are: This section gives the samples taken and checked average SCC score for all cows closely because their cell counts • Faulty milking procedures at different stages of lactation. indicate serious clinical or • Milking equipment The scores on cows fresh under subclinical mastitis problems. • Poor sanitation 50, 50-100, 101-200, 201-300 Also, included along with the • Poor facilities and more than 300 days are cow’s SCC score is the percent • Stray voltage listed. By using this grouping, of the overall herd SCC score • Specific pathogen infection you can see if you are having that each cow is contributing. • Long lactations problems early, in the middle Often you can reduce the SCC or during the latter part of level greatly by simply culling • A high proportion of older the lactation. If a cow’s SCC a few cows. The quickest and cows scores are highest during the easiest way to reduce SCCs early stages of lactation, check is simply to cull the top SCC freshening areas for possible cows. To reduce high SCCs problems. A clean, dry, well- permanently, getting to the root ventilated freshening area is of the problem is necessary. essential for low SCC scores. If the majority of scores are high, examine milking procedures, milking equipment, sanitation practices and treatment procedures, and check for stray voltage.

7 Development of Mastitis A basic knowledge of mammary Invasion of the Udder The potential for invasion is gland and physiology Mastitis results once bacteria greatly increased by bacteria is necessary to understand how pass through the teat duct and that reside in or colonize the teat mastitis develops. The interior multiply in milk-producing tis- duct. Such colonizations occur in of each quarter is composed sues. lactating and dry cows, and the of a teat cistern, gland cistern, Microorganisms breach the colonizing bacteria may survive milk ducts and glandular tissue teat duct in several ways. Be- for months, serving as sources (Figure 2-A). The glandular tween milkings, microorganisms of bacteria for infecting the gland. tissue or secretory portion may pass through the teat duct The practice of dipping with contains millions of microscopic by multiplying inside the duct, or an effective bacteriacide before sacs called alveoli (Figure 2-B). by physical movement resulting and after each milking greatly Each alveolus is lined with milk- from pressure placed on the teat reduces teat duct colonization. producing epithelial cells and end as the cow moves about. To better understand the is surrounded by muscle cells During machine milking, micro- important difference among that contract and squeeze milk organisms may be propelled into mastitis-causing organisms, from the alveolus during milking. or through the teat duct into the the following list summarizes Blood vessels bring nutrients to teat cistern. contagious and environmental each alveolus, where epithelial mastitis. cells convert them into milk. Between milkings, milk accu- mulates in the alveolar spaces, milk ducts and cisterns. During milking, the accumulated fluid is removed through the teat ducts.

Figure 2. Structure of the mammary gland showing teat and gland cisterns, milk ducts and glandular tissue (A). Glandular tissue is made up of many microscopic sacs called alveoli that are lined by milk-producing epithelial cells (B). Millions of alveoli are in each mammary gland. 8 Contagious Versus Environmental Mastitis, Understanding the Difference

Controlling Contagious Mastitis Controlling Environmental Mastitis

Caused by: Caused by: agalactiae (S. agalactiae) Coliforms aureus (S. aureus) Streptococcus dysgalactiae (S. dysgalactiae) Klebsiella pneumoniae Klebsiella oxytoca Primary source: Enterobacter aerogenes of infected cows Method of spread: Environmental streptococci From infected quarters to other quarters S. uberis and cows primarily at milking time S. bovis S. disgalactiae Indicators of problem: Enterococcus faecium Bulk tank somatic cell count (SCC) above Enterococcus faecalis 300,000 cells/ml Primary source: DHIA SCC score above 3.2 The environment of the cow More than 15 percent of cows with a DHIA Indicator of problem: SCC score of 5 or greater High rate of clinical mastitis, usually in early Frequent flare-ups of clinical mastitis, often lactation or during hot weather; somatic cell in the same cows count may be low (less than 300,000) Bacterial culturing of cows shows S. Control recommendations: agalactiae and/or S. aureus infections Reduce the number of bacteria to which the teat end is exposed Control recommendations: Develop program to prevent the spread of Improve cleanliness of cow surroundings, bacteria at milking time especially in late dry period and at calving Improve prepping procedures to ensure Eliminate existing infections by treating all clean, dry teats are being milked cows at drying off and culling chronic cows Goals: Goal: Eradicate S. agalactiae from the herd Reduce clinical mastitis to less than 3 percent of the milking cows/month Reduce S. aureus infections to less than 5 percent of the cows in the herd

Refer to the following discussion for more detail on the organisms.

9 Controlling Contagious Mastitis infections Controlling Environmental Mastitis remain the largest mastitis problem on North Dakota dairy Prevention: Teat dipping: farms. The cure rate with antibiotic • Reduce the number of • Post milking teat dipping with therapy during lactation is very bacteria to which the teat end a germicidal (germ-killing) dip is exposed. is recommended low. Many “staph” cows become • Controls the spread of chronic and have to be culled. Environment: contagious mastitis • Keep the cow environment as • Exerts no control over responds well to antibiotic therapy clean and dry as possible. coliform infections and can be eradicated from dairy • Prevent sows from having • Barrier dips are reported access to manure, mud or herds with good mastitis control to reduce new coliform pools of stagnant water. practices, including teat dipping infections; however, they do • Know that the dry-cow and dry-cow treatment. not appear to be as effective environment is as important against environmental Streptococcus dysgalactiae may as the lactating-cow streptococci and the live almost anywhere: in the udder, environment. contagious pathogens rumen and feces, and in the barn. • Keep the calving area clean. • Attempts to control They can be controlled with proper • Properly design and maintain environmental mastitis during sanitation and are moderately free stalls. the dry period, using either germicidal or barrier dips, susceptible to . Bedding: have been unsuccessful Prevention — • Bacteria numbers in Improved milking procedures: bedding depend on available Dry-cow therapy: • Milk clean, dry teats. nutrients, amount of • Recommended for all contamination, moisture and quarters of all cows at drying- • Keep liner slips to a minimum. temperature. off • Teat teat dip with an effective • Inorganic materials (such as • Helps control environmental germicidal teat dip. crushed limestone or sand) streptococci during the early • Maintain the milking system. are low in nutrients and dry period Eliminating infections: moisture, and thus bacteria. • Has little or no value in • Treat all quarters of all cows • Finely chopped organic controlling coliforms at drying-off with antibiotic bedding (such as sawdust, • Not effective during the products specifically designed shavings, recycled manure, period prior to calving for dry-cow therapy. pelleted corncobs, various Backflushing milker claws • Cull chronically infected cows. seed hulls, chopped straw) are frequently high in between cows: Steps for controlling mastitis bacteria numbers. • Will not control environmental and reducing somatic cell mastitis counts: • Teat dip. Proper milking procedure • Dry-cow treat. important: • Practice proper milking • Wash teats, but not the procedure. udder. • Use a properly functioning • Clean and dry teats before milking system. attaching the milking • Maintain a clean, dry machine. environment for the cows. • Milking wet udders likely will • Cull chronic mastitis cows. increase mastitis. • Use the DHIA SCC program to monitor mastitis in the herd. 10 Proper Milking Procedures Proper milking procedures are Pre-dipping may be beneficial important for the prevention of in reducing mastitis, but the Pre-dipping: mastitis and ensuring complete actual dipping, dip contact time • A germicidal teat dip reduces milk removal from the udder. and wiping with a towel increase environmental mastitis during Cow Movement: Cows the total milking time. If the lactation by 50 percent. should be moved in a quiet, dip is not wiped off, excessive • Be sure the teat dip is gentle manner. If cows are chemical residues in milk may removed from teats before frightened or hurried, the occur. If contact time is not attaching the milking machine milk letdown process may sufficient, then this is a very to prevent contamination of be disturbed, so avoid rough expensive pre-milking regime. the milk. handling. Milking Unit Attachment Milking machine: Mastitis Detection: Milking and Detachment: To attach the • Maintain and operate It may begin with a check of all milking unit to the teats, apply properly because badly quarters for mastitis. Stripping the cluster, allowing a minimum functioning milking machines result in frequent liner slips, milk onto the floor in a milking of air admission and adjust to and teat-end impacts will parlor or flat barn is acceptable. prevent liner slip. Air entering the increase environmental Any cows that show clinical unit may cause the propulsion mastitis. mastitis should be examined of mastitis organisms from one Nutrition: and appropriate action taken. If infected teat into a noninfected • Proper nutrition will reduce the foremilking is not done, milkers teat. This also may happen when risk of environmental mastitis. and herd health people should one teat cup is removed before • Adequate levels of vitamin visually check for inflamed the others. E and selenium reduce the quarters. Machine stripping usually incidence of environmental Udder Preparation: The is not needed on dairy cows. mastitis. object of udder preparation is to Machine stripping should not • Reports differ whether vitamin ensure that clean, dry udders take more than one minute, and A and ß-carotene influence and teats are being milked. no air should be allowed to enter udder health. Single-service paper towels or the teat cups while this is being • Ongoing research at the University of Kentucky washed and dried cloth towels done. A downward force applied indicates copper may play may be used. to the cluster while massaging a role in maintaining the Premilking Teat Dip: The the udder with the other hand is immune system in dairy cattle. procedure for pre-dipping all that is needed. • Feed dairy cattle a balanced involves washing teats with Following milk-out, the ration water and a sanitizer. Then machine should be removed only Vaccines: dry the teats with an individual after the vacuum to the teats is • Not effective in preventing new towel and dip or spray them with shut off. This is accomplished infections the sanitizer. The teats need to most commonly by using a • Research on vaccines to have a 30-second contact with vacuum shut-off valve or milk reduce Escherichia coli sanitizer to kill organisms. Then hose clamp, which prevents the and staphylococcal mastitis wipe the sanitizer dry with the backjetting of bacteria from one infections looks promising towel. Milk the cows and dip teat to another. the teats with the same type of sanitizer to prevent chemical reactions that could cause irritation to teats.

11 Use of Backflushers: Many effective teat dips, base that allows them to stay in Backflushers have been including iodine at 0.1 percent, the udder longer. They are not developed to sanitize the liners 0.5 percent and 1 percent, and constantly being milked out of and claws between milkings. chlorhexidine at 0.5 percent, the udder, as is the case with Most units on the market have are available. Also, although lactation therapy. Antibiotics can four or five cycles. The first cycle hypochlorite at 4 percent with a be given in higher quantities is a water rinse, followed by an sodium hydroxide content less because milk levels and iodine or similar sanitizer rinse, than 0.05 percent is not labeled antibiotic residues are not a clear-water rinse and positive for teat dipping, it was effective in concerns. air-dry cycle. field trials.. Effective coverage of While dry treatment is Research has demonstrated the teats is more important than very effective, it must be that backflushers do reduce the type of dip being used. administered properly, and the number of bacteria on the If contagious bacteria (S. dry cows must have favorable liners between cows but do not agalactiae, S. dysgalactiae, S. environmental conditions. reduce the number of bacteria aureus or Mycoplasma) are Teat ends must be scrubbed on teats. Backflushers also may in your herd, you must dip the clean with cotton alcohol stop the spread of contagious whole teat to the base of the pads before injecting the dry organisms, but this also can udder to stop the spread. Wand treatment. If the teat ends are be accomplished at a much sprayers are acceptable for not cleaned properly, you may lower cost by teat dipping. herds that have environmental inject very high numbers of Backflushing has no effect mastitis because teat bacteria into the udder, which on environmental pathogens colonization is not a factor. Hand- would overwhelm the antibiotic that are encountered between held spray bottles are the most just administered. Unsanitary milkings. ineffective method of getting treatment procedures cause Teat dips are effective against proper coverage of dip on the rather than eliminate mastitis. all mastitis organisms. They have cow’s teats, so they should not Management of dry cows been shown to effectively reduce be used. Dip cups, on the other is very important in mastitis mastitis caused by S. aureus and hand, give the best coverage. control. If dry cows are exposed S. agalactiae, the most common Dry-cow Therapy. Dry-cow to muddy or dirty conditions, the types of mastitis. treatment is administered after risk of mastitis will increase. This Considerable controversy the last milking of the cow before is especially true at calving time; surrounds the effectiveness of the dry period. Take care to cows are under much stress teat dipping on environmental scrub the teat end with cotton during this period. If an udder is pathogens E. coli and S. uberis. and alcohol before infusion and exposed to wet, dirty conditions, Some research has shown to use teat dip after infusion. mastitis will increase. that teat dipping does not Many antibiotics are If you believe that your control these organisms. These available for dry-cow therapy. dry-cow therapy program is pathogens are found in the High levels of penicillin and ineffective, that may be because cow’s surroundings; if mud is dihydrostreptomycin, the of poor treatment procedures udder deep, the teat dip will be cloxacillins and other products and/or improper management of removed and a new infection specifically for dry treatment are the cows during the dry period may occur. effective. and at calving. Dry-period therapy has been accepted because antibiotics can be put into a slow-release

12 Milking Machine Inspection and Maintenance Checklist Before each milking: Dealer checks and service Check (every six months or 1,250 hours): ❏ vacuum controller Checks to be made: Equipment needed: ❏ milking vacuum ❏ air delivery by ❏ hoses and teatcup liners for holes or tears vacuum pump air flow meter ❏ pulsators ❏ reserve air flow remaining( ❏ air admission holes in claw or tailpiece of pump capacity with units liner operating but not on cows) air flow meter ❏ pulsator rate Weekly (or every 50 hours of operation): (pulsations per minute) stop watch or clock ❏ pulsator function Set aside one day each week, such as every and ratio vacuum recorder Monday morning, to perform these checks. ❏ vacuum level vacuum gauge Check ❏ line voltage voltmeter ❏ and clean vacuum controller ❏ and clean pulsator filters Maintenance items: ❏ belts on vacuum pumps ❏ Check all gaskets, flappers, “O” rings, and ❏ oil reserve on vacuum pump caps which come in contact with milk. ❏ if it is time to change liners (every 1,000- Replace if worn. 2,000 milkings, or as recommended) ❏ Clean all electric pulsator selectors and ❏ and clean moisture trap activators. Check all solenoids and coils. ❏ automatic take off-equipment (especially Clean all plungers and vacuum lines. vacuum shut off) ❏ Overhaul pneumatic pulsators. Repair milk Monthly (or every 250 hours): supports, milker units, etc. Set aside one day each month, such as the first Every year (or 2,500 hours of use): Monday, to perform these checks. ❏ Change all solenoid coils, plungers, Check hoses, diaphragms, caps, gaskets, flap- ❏ and clean the pulsators pers and rubber vacuum connectors. ❏ and clean vacuum pulsation lines ❏ Check electric timer controls, switches, ❏ vacuum pump(s) motors, and parts. Grease all bearings. check belts for wear and tension ❏ Check milk pump seal, rubber spring and clean screens clearances. Change gaskets. change filters on vacuum pump tank Every two years (or 5,000 hours of use): change oil if needed ❏ change liners if it is time ❏ Recondition the entire system, including all motors, pumps, selectors, timers and starters. ❏ Replace all rubber coils, hoses, gaskets, “O” rings, springs and plungers. Clean the entire pipeline system.

For more information on milking machines, refer to, “The Modern Way to Effective Milking,” published by the Milking Machine Manufacturers Council of the Farm and Industrial Equipment Institute, 410 N. Michigan Avenue, Chicago, IL 60611-4251.

Culling: Culling cows for candidates for culling because procedures and culling only old, mastitis is effective in eliminating they no longer may be profitable chronic cows usually is more mastitis in the herd. Cows that as the result of discarded milk profitable than trying to control have been treated many times and antibiotic costs. Carrying mastitis by routine culling. in a single lactation are prime out preventive mastitis control 13 Proper Treatment Procedures • Insert only the tip of the • Dry teats with individual tow- canula into the teat end. Do els. In every program, some not allow the sterile canula medication, plus dry-cow to touch anything prior to • Discard one or two squirts of treatment protocol, is required. infusion. milk from each teat. This is especially important with • After infusion, remove the • Dip teats in germicidal teat intramammary infusions. Take canula, squeeze the teat end dip. extreme care whenever infusing with one hand and massage • Allow 30 seconds of contact anything into a cow’s udder. the antibiotic up into the time before wiping off the teat Careless treatment procedures quarter with the other hand. dip with an individual towel. can result in udder infections • Dip teats in an effective • Thoroughly scrub the teat end resistant to treatment. Approach germicidal teat dip after treatment. with a cotton swab soaked in treatment in the same way a alcohol. If a composite sample surgeon approaches surgery: is being taken from all four • Wash your hands with soap quarters, start with the teat and water. How to Collect farthest from you and work Milk Samples toward the closest teat. Use a • Wash teats and the udder in clean swab on each teat. sanitizing solution. Even the most successful milk- • Open the sterile tube under • Thoroughly dry teats and the ing management program needs udder with individual towels. the teats. Hold the tube at an to culture samples when prob- angle so that foreign material • Dip teats in an effective lems arise. Positive identification cannot fall into the opening. germicidal teat dip. of invading organisms can speed Do not allow anything to come • Allow 30 seconds of contact up solutions to difficult chal- in contact with the mouth of time before wiping off teat dip lenges. the tube. Collect one or two with an individual towel. squirts of milk from each When taking samples, taking quarter, starting with the • Thoroughly scrub the teat end a sample that is not contami- with a cotton swab soaked closest quarters and working nated is imperative for accurate in alcohol. If all four quarters toward the ones farthest away. lab analysis. Here are the steps are being treated, start by • Close the container before cleaning the teat farthest to collecting milk samples: removing it from beneath the from you and work toward the • Label sterile tubes and fill out teats. closest teat. forms ahead of time. (Tubes • Refrigerate the samples until • Use commercial antibiotic with screw caps are pre- they reach the lab. If samples products in single-dose ferred.) will not reach the lab within 24 containers formulated for • Wash your hands in soap and hours, they should be frozen intramammary infusion. water. and kept frozen until they For dry-cow therapy, use reach the lab. commercial antibiotic products • Wash the teats in a sanitizing specifically formulated for dry- solution. cow therapy in single-dose containers. Treat teats nearest to you first, then those farthest away to prevent contaminating clean teat ends. For more information, see other NDSU Extension Service publications in the Mastitis Control Programs series: • “Proper Milking Techniques,” AS1126 • “Troubleshooting a Mastitis-problem Herd,” AS1128 • “Milk Quality Evaluation Tools for Dairy Farmers,” AS1131 14 15 The NDSU Extension Service does not endorse commercial products or companies even though reference may be made to tradenames, trademarks or service names. NDSU encourages you to use and share this content, but please do so under the conditions of our Creative Commons license. You may copy, distribute, transmit and adapt this work as long as you give full attribution, don’t use the work for commercial purposes and share your resulting work similarly. For more information, visit www.ag.ndsu.edu/agcomm/creative-commons. For more information on this and other topics, see www.ag.ndsu.edu County commissions, North Dakota State University and U.S. Department of Agriculture cooperating. 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