Historic, Archive Document Do not assume content reflects current scientific knowledge, policies, or practices. ry Services =pidemiology and Animal Health \S October 2008 Milking Procedures on U.S. Dairy Operations, 2007 FS DEC 0 3 2008 | Milking frequency In 2007, the U.S. Department of Agriculture’s (USDA) National Animal Health Monitoring System (NAHMS) |« eS PREP | conducted the Dairy 2007 study. In all, 17 of the Nation’s Evidence suggests that increasing the times |p er day major dairy States* participated in the study. These fresh cows (cows less than 30 days in milk) are milked States were divided into two regions and represented increases milk production and that the increased 79.5 percent of U.S. dairy operations and 82.5 percent of production persists throughout lactation.° * More than 9 U.S. dairy cows. One objective of Dairy 2007 was to of 10 operations (91.8 percent) milked fresh cows twice describe milking procedures and associated practices daily compared with 7.6 percent that milked fresh cows and to estimate the prevalence of contagious mastitis 3 or more times daily. The percentage of operations that pathogens. milked fresh cows three times per day or more increased Contagious mastitis is caused by pathogens that as herd size increased. typically spread from cow to cow during milking. The majority of operations milked cows other than Environmental mastitis is caused by teat-end exposure fresh cows twice daily (92.5 percent). As was observed with fresh cows, the percentage of operations that to an environmental pathogen. | Proper milking procedures can help control, both contagious mastitis milked cows three times per day increased as herd size and environmental mastitis. increased. Milker training Use of gloves Although the owner/operator milked the majority of Mastitis pathogens can be spread from infected to uninfected cows during milking via the milkers’ hands. cows on most operations, the largest percentage of cows (68.2 percent) were on operations in which hired Using latex or similar gloves can reduce the spread of workers milked the majority of cows. Training milking mastitis, but gloves should be disinfected between cows.” personnel in the proper procedures used to milk cows and providing reasons for the procedures are usually Approximately half the operations (55.2 percent) reported that milkers wore gloves to milk all cows. Ongoing processes. However, 76.8 percent of cows were on operations in The Dairy 2007 study reported that milker training increased as herd size increased, with 42.3 percent of which gloves were used, suggesting the practice is more small operations (fewer than 100 cows) training milking common on large operations. personnel compared with 75.3 percent of medium operations (100 to 499 cows), and 97.8 percent of large Clinical mastitis milking practices operations (500 or more cows). A higher percentage of operations in the East region Milking cows with clinical mastitis at the end of (48.9 percent) did not provide milker training compared milking, with a separate milking unit, or in a separate with operations in the West region (15.6 percent). In the string can reduce the exposure of noninfected cows to West region, hired workers milked the majority of cows mastitis organisms. ° Approximately one of three on 82.7 percent of operations, while in the East region operations (34.9 percent) used a separate milking unit to the owner/operator milked the majority of cows on milk mastitic cows. A higher percentage of large 64.1 percent of operations. Almost all operations that operations (83.4 percent) milked mastitic cows in a trained milkers (97.1 percent) trained them on the job. separate string from healthy cows compared with small and medium operations (29.8 and 33.4 percent, respectively) [figure 1]. *States/Regions: e West: California, Idaho, New Mexico, Texas, and Washington e East: Indiana, lowa, Kentucky, Michigan, Minnesota, Missouri, New York, Ohio, Pennsylvania, Vermont, Virginia, and Wisconsin United States Department of Agriculture « Animal and Plant Health Inspection Service Safeguarding American Agriculture Figure 1. Percentage of Operations by Method Used for Milking Figure 2. Percentage of Operations by Type of Predip Used Cows with Cilnical Mastitis, and by Herd Size: Predip Type Percent 100 Foam Size of Operation nonlabeled Hismall (fewer than 100) disinfectant 80 [__|Medium (100-498) [=] Large (500 or more) Foam, labeled =| All operations disinfectant Predip cu Rontabeted disinfectant Predip cup label disinfectant Spra r 0 poniabeed Using a separate milking In a separate strin disinfectant unit from healthy cows from healthy cows M Milking Practice Teat preparation Percent Premilking teat disinfection has been shown to reduce environmental bacteria on the teat surface, Forestripping reduce bacterial counts in milk, and may decrease the incidence of new infections.’ While there are many different methods to accomplish this, disinfectants Forestripping cows stimulates milk secretion from should be tested for efficacy and labeled for teat mammary tissue, allows the milker to observe any disinfection. abnormalities in the milk, and removes milk with a higher Methods of washing teats include a water hose with concentration of somatic cells, thereby improving milk disinfecting solution, a water hose without disinfecting quality.’ Overall, 92.6 percent of operations forestripped solution, or disinfecting wipes. Using single-use towels some or all cows. helps prevent the spread of mastitis pathogens from If forestripping is performed before teat disinfection infected cows to noninfected cows.’ More than 4 of 10 or while disinfectant is still on the teat, it may reduce the large operations (41.5 percent) used a wash pen prior to transfer of organisms from the milker to the teat. Teats entering the parlor, compared with less than 3 percent of may become recontaminated with bacteria if the small or medium operations. There were no differences forestripping is performed after drying.® Over half the by herd size in the percentages of operations that used operations that forestripped any cows (56.7 percent) did water hoses, with 2.8 percent of operations using water so prior to teat disinfection or after teat disinfection but hoses with disinfectant and 4.2 percent using water prior to drying, while 43.3 percent did so after hoses without disinfectant. A single-use towel using a disinfection and/or drying. labeled disinfectant was the predominant wet-wipe method used on 8.5 percent of operations. Drying Predip disinfectants can be applied via sprayer, cup, or foamer. Almost half of all operations (49.0 percent) If teats are wet prior to milking, they should be dried applied a labeled disinfectant in a predip via a predip cup with a single-use towel to decrease the risk of new (figure 2), and no differences were observed across herd infections. Liner slips—which occur more frequently sizes. A higher percentage of operations in the East when teats are wet—can cause rapid air movement region used a predip cup to apply a labeled disinfectant inside the milking claws, resulting in injection of bacteria to teats, compared with operations in the West region. into the teat canal.’ In summer and winter, single-use paper and cloth towels were used to dry teats on approximately 55 and 21 percent of operations, respectively, while multiple-use paper and cloth towels were used on 0.6 percent and 7.1 percent of operations, respectively. United States Department of Agriculture = * Animal and Plant Health Inspection Service + Safeguarding American Agriculture Automatic takeoffs Milk from cows treated with antibiotics should be discarded for a specified withdrawal period, as directed Incorrectly removing the milking unit can have a by the drug manufacturer via the product label. detrimental impact on udder health. Automatic takeoffs Manufacturers are required to go through an exhaustive may improve teat-end condition by promptly removing drug approval process that determines the withdrawal the milking claws at a predetermined milk-flow rate.'° A period. If approved drugs are used in the manner higher percentage of medium and large operations (76.9 prescribed on the label, producers can use the and 89.5 percent, respectively) used automatic takeoffs withdrawal period stated on the label, Knowing that the compared with 30.2 percent of small operations. milk does not contain violative drug residues. However, producers may use on-farm drug-residue testing to be Postmilking teat dipping confident that the milk they are selling is free from violative drug residues. Applying postmilking teat disinfectant kills mastitis One caveat of on-farm drug testing is that the pathogens before they can enter the teat canal and is residue testing kits are approved for bulk tank milk, not the single most effective practice of reducing the for individual cows. Using residue tests on individual incidence of contagious mastitis.* More than three of four cows may result in milk being discarded, even though it operations dipped teats with a labeled postdip in is below the violative level. Almost half the operations summer and winter. Approximately 13 percent of (49.8 percent) performed milk residue testing, with a operations sprayed teats with a commercial postdip in higher percentage of medium operations (64.5 percent) summer and winter. About 5 percent of operations testing compared with small operations (44.2 percent). performed no teat disinfection. While there are numerous residue screening tests The majority of operations (about 70 percent) used available, the majority of operations that tested for iodophor compounds as predips and postdips in both residues (62.9 percent) used Delvotest®. Nine of 10 summer and winter. Chlorhexidine was the next most operations that screened for antibiotic residues common compound and was used by about 13 percent (90.9 percent) tested individual cows that were recently of operations. treated for mastitis, and about 6 of 10 operations Postmilking barrier teat dips provide additional (57.8 percent) tested fresh cows. protection against new coliform intramammary infections, although germicidal dips appear to provide Dry-cow therapy better protection against environmental streptococci and contagious pathogens.” Approximately one of four The purpose of dry cow therapy is to prevent new operations used a barrier teat dip on all cows all the time inttamammary infections during the dry period and to (24.5 percent), and no differences were observed across treat subclinical udder infections.'® Dry-cow therapy herd sizes. About two-thirds of operations (66.7 percent) includes the use of external sealants, internal sealant did not use a barrier teat dip. A higher percentage of infusions, and antimicrobial infusions. operations in the East region (68.4 percent) did not use External teat sealants coat the exterior of the teat to a barrier dip compared with operations in the West prevent bacterial entrance into the gland. More than 8 of region (49.0 percent). 10 operations (82.8 percent) did not use an external teat sealant at dryoff, while 14.0 percent of operations used a Backflush systems sealant on all cows at dryoff. There were no differences across herd sizes or by regions. A backflush system is used to wash the milking claw Internal teat sealants are another way to supplement or cluster between cows, which reduces the spread of the teat’s defenses against bacterial infections. Proper contagious mastitis pathogens. || A total of 6.8 percent of hygienic insertion of the teat sealant is important to operations used a backflush system. Although no prevent contamination of the mammary gland."° A higher differences in the use of a backflush system were percentage of medium and large operations used observed by herd size, there was a regional difference: internal teat sealants on all cows at dryoff (45.7 and 49.0 20.9 percent of operations in the West region used a percent, respectively) compared with 22.7 percent of backflush system compared to 5.4 percent in the East small operations. Overall, 30.1 percent of operations region. used an internal teat sealant. The use of inttamammary antibiotics at the time of Residue testing dryoff can cure many existing infections and reduce new infections. Almost 1 of 10 operations did not use any dry- Every tanker load of milk in the United States is cow treatment. Some of these operations were organic tested at the milk plant for the presence of specific operations where the use of antibiotics is not allowed. antibiotics prior to processing. Consequences of a For cows treated with dry-cow intramammary antibiotics, positive test may include discarding the entire truckload the most commonly used antibiotics were cephapirin and of milk and suspension of the producer’s permit to sell penicillin G/dihydrostreptomycin (31.0 and 36.9 percent milk. of cows, respectively) [figure 3]. United States Department of Agriculture * Animal and Plant Health Inspection Service * Safeguarding American Agriculture T a Figure 3. For Cows Treated with Dry-Cow Intramammary Antibiotics NATMIONiAL li j | During the Previous 12 Months, Percentage of Cows Treated, by Type of Antibiotic For more information, contact: | | Antibiotic 1022 | USDA:APHIS:VS:CEAH Ceftlofur hydrochloride NRRC Building B, M.S. 2E7 Cephapirin 2150 Centre Avenue (benzathine) Fort Collins, CO 80526-8117 Cloxacillin (benzathine) 970.494.7000 E-mail: NAHMS @aphis.usda.gov Erythromycin http://nahms.aphis.usda.gov Novoblocin #N531.1008 Penicillin G (procaine) Penicillin G/ Dihydrostreptomycin Pentcillin G/ The U.S. Department of Agriculture (USDA) prohibits Novobiocin discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or part of an individual’s income is derived from any public assistance program. (Not all To review complete reports from the Dairy 2007 prohibited bases apply to all programs.) Persons with study, visit the NAHMS Web site at: disabilities who require alternative means for communication of http://nahms.aphis.usda.gov program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720-2600 References (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence 1. A practical look at environmental mastitis. National Mastitis Avenue, S.W., Washington, D.C. 20250-9410, or call (800) Council Web site. Accessed May 2008. 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal http://www.nmconline.org/contmast.htm opportunity provider and employer. 2. LeBlanc SJ, Lissemore KD, Kelton DF, Duffield TF, Lesslie KE. 2006. Major advances in disease prevention in dairy Mention of companies or commercial products does not imply cattle. J Dairy Sci 89:1267-1279. recommendation or endorsement by the U.S. Department of 3. Pearson RE, Fulton LA, Thompson PD, Smith JW. 1979. Agriculture over others not mentioned. USDA neither guarantees Three times a day milking during the first half of lactation. J nor warrants the standard of any product mentioned. Product Dairy Sci 62:1941-1950. names are mentioned solely to report factually on available data 4. Dahl G. 2003. Increased milking frequency in fresh cows: and to provide specific information. effect on production persistency. Proceedings of the Western Canadian Dairy Seminar. 5. Roberson JF. 1999. The epidemiology of Staphylococcus aureus on dairy farms. National Mastitis Council Annual Meeting Proceedings. 6. Gonzalez RN. 1996. Mycoplasma mastitis in dairy cattle: ilf ignored, it can be a costly drain on the milk producer. National Mastitis Council Regional Meeting Proceedings, p 37 7. Milking tips from the National Mastitis Council. National Mastitis Council Web site. Accessed February 2008 http://www.nmconline.org/milktips.htm 8. Johnson AP. 2000. A proper milking routine: the key to quality milk. National Mastitis Council Annual Meeting Proceedings. p 104 9. Pankey JW. Premilking udder hygiene. 1989. J. Dairy Sci 72:1308-1312 10. Reid, DA, Johnson, AP. Trouble shooting herds with poor teat condition. National mastitis Council Website. Accessed May 2008. http://www.nmconline.org/articles/tblshootteat.pdf 11. Hogan JS, Harmon RJ, Langlois BE, Hemken RW, Crist WL. 1984. Efficacy of an iodine backflush for preventing new intramammary infections. J Dairy Sci 67:1850-1859. 12. Kelton DF, Godkin MA. Mastitis culture programs for dairy herds. National Mastitis Council Annual Meeting Proceedings (2000). http://www.nmconline.org/articles/cultureprg.pdf P.55. 13. NMC Factsheet-Dry Cow Therapy. National Mastitis Council Web site. Accessed July 2008. http://nmconline.org/drycow.htm United States Department of Agriculture * Animal and Plant Health Inspection Service + Safeguarding American Agriculture